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Topics - sgottlieb

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TAC Visual / Lake Sonoma OR from Saturday May 20th
« on: Yesterday at 01:52:49 PM »
I decided to go to head to Lake Sonoma yesterday afternoon (Saturday) as the predicted conditions were excellent.   Only two others showed up -- Matt Marcus and Shneor Sherman, which was surprising as this was the best weather in terms of temperature/humidity/wind, etc. that we've had in awhile.  It turned out to be a dark night with pretty good seeing.  I made a SQM reading of 21.45, which beats most locations close to the bay area, though the Milky Way wasn't that impressive, so the transparency wasn't ideal.

Unfortunately, we were interrupted for at least an hour and a half by a parade of cars/pick-up trucks that drove into the large Lone Rock lot every few minutes, apparently looking for the rowdy party that took place in the equestrian area just below Lone Rock.  There was also an unusually high amount of road traffic on Rockpile Road, so not a very relaxing evening.  Around 12:30 it finally quieted down and fortunately stayed that way.

One highlight was the type IIP supernova SN 2017eaw in NGC 6946 -- the appropriately named Fireworks Galaxy, which was discovered a week ago on May 14th.  It was easily visible (close to mag 12.5) in the halo of the galaxy, 1.0' west and 2.4' north of the center, and formed a wide pair with a fainter star.  This is the 10th supernova in the past century in the NGC 6946 (I believe I've viewed 4 of these) and it holds the record for the most prolific SN producer: SN 1917A, SN 1939C, SN 1948B, SN 1968D, SN 1969P, SN 1980K, SN 2002hh, SN 2004et, SN 2008S, and now SN 2017eaw.  It may still be on the rise -- in any case it was easy to see in Matt's C-8 and certainly a 6" (or smaller) will do the trick.  Check it out if you view in the next week!!

I also viewed Comet C/2015 V2 (Johnson) in Bootes, which was a bright 7th magnitude (visible in binoculars) and displayed a faint but obvious tail that extended through much of the 13mm Ethos eypeiece field.  It displayed a large coma and an intensely bright nucleus.  This is easy to find and well placed mid-evening, so another one not to miss.

As far as deep-sky objects, I took notes on about 3 dozen galaxies -- mostly working on two projects.  One is to pick up very faint companions to NGC galaxies.  The companions are sometimes in the IC, but often just carry a PGC designation.  The other project is galaxy mergers -- where two nuclei can be resolved within a single common halo.  A good example is NGC 5259, a faint galaxy in Canes Venatici, which I viewed around 1:30.  The second nuclei, labeled in this image as Holmberg 533B (Eric Holmberg studied double galaxies as part of his doctoral thesis in Sweden in the 1930's), was tough at 375x but definitely visible most of the time.

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Observing Intents / OI - Lake Sonoma Saturday 5/20
« on: May 20, 2017, 05:24:20 PM »
I'll be at Lake Sonoma's Lone Rock tonight at sunset for perhaps the last good look at Spring galaxies as they start to slip into the western sky and become less convenient to view.

3
TAC Visual / Action on Jupiter
« on: May 03, 2017, 07:58:29 PM »
With the moon now dominating the early evening skies, I've been doing a little Jupiter gazing in my driveway.  On Sunday night, Europa starting transiting the disk of Jupiter around 11:30 and last night (Tuesday) it was Io's turn.  It reached the limb around 10:00 PM and after 10:30, its shadow started marching across the face of Jupiter along the north equatorial belt.  This last sequence of events repeats next Tuesday, though a bit later.

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Observing Reports / Springtime galaxies...observations
« on: April 06, 2017, 02:46:30 PM »
Here are my 10 favorites from last Tuesday night's observations.  Images (except for the Hydra I cluster) are from the Sloan Digital Sky Survey (SDSS).  The last image of the overlapping pair NGC 3314 is from the HST, of course.

Steve
------------

IC 2207
07 49 50.9 +33 57 44
V = 14.2; Size 2.0'x0.25'; PA = 124°

This member of the Flat Galaxy Catalogue appeared as a very faint, extremely thin ghostly streak, over 10:1 NW-SE, ~1.1'x0.1’, with a low fairly even surface brightness. It increased in length with averted vision, so the outer tips were a bit fainter. A mag 15.5 star is 30" NE of center.




IC 491
08 03 55.0 +26 31 14
V = 14.9; Size 0.6'x0.25'; PA = 114°

I took a look at this close galaxy pair at both 260x and 520x. The brighter eastern galaxy appeared faint, small, round, 12" - 15" diameter, quasi-stellar or stellar nucleus. Situated within a N-S string of mag 9 to 10.5 star including a mag 10.2 star 1.5' NW. IC 491 forms a very close pair (non-physical) with PGC 1779405 0.5' NW. This 16th magnitude galaxy appeared extremely faint and small, 6" diameter, only occasionally pops. The nearby bright star made the detection difficult.




IC 496 = IC 2229
08 09 44.2 +25 52 54
V = 14.6; Size 0.55'x0.3'; PA = 30°

IC 496 was resolved into a close pair (physical), separated by just 19" E-W. The brighter western component (IC 496A = LEDA 93095) appeared faint, very small, round, 10"-12" diameter. The fainter eastern galaxy (IC 496B = PGC 22903) was very faint, extremely small, round, 6" diameter. An 18" pair of mag 13.5/14 stars lies 1.5' SSE. Located 7' WNW of mag 6.4 13 Cancri (K0-type).




IC 480
07 55 23.2 +26 44 36
V = 14.2; Size 1.7'x0.3'; Surf Br = 13.4; PA = 168°

This edge-on appeared fairly faint, moderately large, very elongated 6:1 NNW-SSE, 0.9'x0.15', slightly brighter core. Bulges very slightly but no nucleus seen. Situated in a busy star field with a mag 15.5 star 1.2' S (collinear with the major axis). A mag 10.9 star lies 2.5' NW. This galaxy lies at a distance of ~200 million light years, which implies a true diameter of ~100,000 l.y. for the galaxy.




NGC 3067 + Quasar
09 58 21.1 +32 22 12
V = 12.1; Size 2.5'x0.9'; Surf Br = 12.8; PA = 105°

NGC 3067, about 70 million l.y. distant, appeared fairly bright, moderately large, elongated 5:2 WNW-ESE. The brighter elongated central section was mottled and appeared to have a sharp light cut-off (dust lane) on the northern flank. The eastern end of the galaxy has a lower surface brightness, probably due to dust.

3C 232 = Ton 469, a distant quasar with a redshift of z = .531 (light-travel time of 5.3 billion years), lies 1.9' due north. It was easily visible at 375x as a very faint mag 16 star. A brighter mag 15 star is 1.4' WSW of the quasar. This QSR was involved in one of Halton Arp's controversies. A neutral Hydrogen "bridge" appears to connect the quasar and NGC 3067. Arp proposed the QSR was ejected from NGC 3067, a theory which was rejected by mainstream astronomers.




Arp 174 = NGC 3068 + PGC 87670
09 58 40.1 +28 52 39
V = 14.3; Size 1.1'x0.9'; Surf Br = 14.1

NGC 3068 is the brighter of a close, interacting pair of galaxies with PGC 87670 just 36" SE (between centers). It lies in Leo, about 290 million l.y. distant. The NGC appeared fairly faint, fairly small, contains a small bright core, ~15" diameter. The oval halo has a very low surface brightness and extends ~25"x18" E-W. The companion was extremely faint, round, only 10" diameter at most. Although I couldn't hold this compact galaxy continuously (V = 15.6), it was often visible. There was no sign of a connection between the pair or the long, diffuse tidal tail to the southwest (lower right).




Arp 191 = VV 239 = UGC 6175
11 07 20.2 +18 25 52
Size 1.9'x1.1'

This interacting pair in Leo resides at a distance of ~375 million light years. The brighter and larger northeastern component (VV 239a) of Arp 191 appeared faint, small, elongated 3:2 ~N-S, 0.3'x0.2’.
VV 239b, just 20" SW, appeared very faint, round, just 8" diameter. There was no sign of the tidal tail to the east of VV 239a.




Arp 198 = VV 267 = UGC 6073
10 59 46.0 +17 39 10
Size 1.3'x0.9'

Arp 198 is an overlapping pair consisting of face-on spiral and a thin edge-on that extends right to the nucleus of the face-on. Halton Arp classified this pair under his category "Galaxies: Material ejected from Nuclei.” Clearly, he interpreted it as a face-on spiral with a jet extending to the west (right). But this SDSS image clearly reveals it as an overlapping pair very close to a star! There is no sign of distortion in VV 267a, so it is very questionable if they are currently interacting.

At 260x and 375x, the pair appeared as a very faint, fairly small, very elongated glow, ~0.4'x0.1', extending to the southwest of a mag 12.3 star. The faint glow had an unusual "spike" appearance, with a very small "knot" (core of VV 267a = UGC 6073b, the face-on spiral) at most 10" diameter at the northeast end close to the mag 12 star [28" SW of the star]. The spike or tail (VV 267b = UGC 6073a) extends southwest with the combined glow collinear with the star!




Arp 156 = UGC 5814
10 42 38.2 +77 29 42
Size 1.3'x0.8'; PA = 128°

Arp 156 is considered to be a gas-rich post-merger with a major-axis dust lane. This Draco galaxy is pretty distant at ~480 million l.y. It appeared fairly faint, moderately large, oval 4:3 or 3:2, contains a brighter core with much fainter asymmetric extensions ~40"x 30" NW-SE. The SE extension seemed cut off (due to dust?). A mag 12 star is 1.2' SW and a mag 10.7 star is 1.9' S. Also nearby is a mag 9.3 star (SAO 7190) 4.4' SW and a mag 7.8 star (HD 92319) 5.3' SSW. The view was significantly improved moving with these two brighter stars outside the field.




AGC 1060 = Hydra I Cluster
10 36 48 -27 32

I logged 19 galaxies in the central region of the Hydra I cluster — in preparation for an article in Sky & Telescope next year. This cluster is one of the closest fairly rich clusters to our Local Group, after the Virgo cluster, the Fornax cluster and the Antlia cluster. It has are some interesting similarities with the well-known Virgo cluster. The cluster is roughly 3 times the distance of the Virgo cluster and extends about ? the size in the sky — so both cluster have a similar linear dimension as well as a comparable number of members. Furthermore, both clusters have an giant X-ray emitting galaxy near the core — M87 in the Virgo cluster and NGC 3311 in the Hydra I cluster. Also like M87, NGC 3311 a huge number of globular clusters, estimated at ~16,000 GCs! It’s partner, NGC 3309, is also a giant elliptical but has a normal number of globular clusters — perhaps its retinue was stolen but its larger neighbor.

The cluster surrounds a naked-eye mag 4.9 star, which makes finding the cluster pretty easy in a dark sky, but also makes viewing some of the nearby galaxies pretty tough. Although ESO 501-047 was picked up pretty easily (I had previously seen this one with a 13-inch from Costa Rica, ESO 501-052 was pretty tough and of course the bright star had to be kept out of the field. A fascinating member is NGC 3314, near the bottom of the image above. It consists of two large spiral galaxies, which are directly overlapping! The dust lanes of the foreground galaxy are silhouette against the background spiral. Visually, though, only the brighter background galaxy is seen as the foreground galaxy has a very low surface brightness.

NGC 3314

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Observing Reports / Springtime galaxies ...finally!
« on: April 03, 2017, 06:35:12 PM »
Last Tuesday (March 28th), with the new moon observing window starting to close, Mark McCarthy and I observed at Kevin Ritschel's ranch in the hills southeast of Hollister (Willow Springs).  The drive south from Berkeley in the afternoon was pretty brutal due to accidents and slowdowns and the usual 2 ½ drive took me an extra hour.  Still, I arrived about an hour before sunset and had plenty of time to set up my 24-inch and eat dinner while it was getting dark.  Mark arrived about a half hour after me and set up his 20-inch before I was finished.

About a half hour after sunset I started scanning in the west looking for Mercury but instead noticed an extremely thin arc, nearly lost in some low clouds and haze along the western horizon -- it was the crescent moon just 25 hours old!  Quite an exquisitely thin sight and totally unexpected.  About 15 minutes later I found Mercury, which was surprisingly bright and high -- both of us were initially unsure it was Mercury as it was so (relatively) high in the west.  But a quick look in Mark's scope (just a non stellar "blob") confirmed it was Mercury.  Turns out it was close to its maximum elongation (about 10° when we viewed it).

By 9:00 it was fully dark, but we could see some illuminated clouds along the western horizon and northern horizons.  Mark measured an SQM reading of only 21.2 or so (subpar for this site), but I believe it hit 21.5 or 21.6 sometime after midnight.  Early on we took a peek at comet 41P/Tuttle-Giacobini-Kresak near the Ursa Major/Draco border in Mark's scope.  This relatively bright and large comet seemed around 8th magnitude and contained a very prominent nucleus.  I also took a quick look at the planetaries NGC 2438 in M46 (Puppis) as well as NGC 2818A in the cluster NGC 2818 (Pyxis).  Neither of these planetaries are physically associated with the associated cluster.

I worked on three different programs in the evening -- each for a couple of hours.  First up was a number of IC galaxies in Gemini, Cancer, Canis Minor and Hydra.   The middle part of the evening was a survey of the central region of Hydra I galaxy cluster, which includes NGCs 3285, 3305, 3307, 3308, 3309, 3311, 3312, 3314, 3315 and 3316.  I took notes on 19 galaxies for a planned article in Sky & Tel next spring.  The cluster is a near twin of the downtown section of the Virgo cluster -- just 3 times as distant!  Late at night I focussed on a number of new (for me) Arp galaxies.  All in all, about 50 objects were viewed over 7 ½ hours.

One interesting galaxy was NGC 3067 in Leo, about 70 million l.y. distant.  The galaxy itself had lots of subtle structure -- logged as fairly bright, moderately large, elongated 5:2 WNW-ESE, mottled elongated central section with a sharp light cut-off (dust lane) on the northern flank.  The eastern end of the galaxy has a lower surface brightness, probably due to dust.  A very faint 16th magnitude star was easily visible 2' north.

This unassuming star is actually a super-luminous quasar (3C 232) at a distance of 5 billion light years and involved in one of Halton Arp's controversies.  A neutral Hydrogen "bridge" appears to connect the quasar and NGC 3067.  Arp proposed the QSR was ejected from NGC 3067, a theory which was rejected by mainstream astronomers.

6
TAC Visual / Colliding Galaxies
« on: March 17, 2017, 02:39:48 PM »
I wanted to mention I have a featured observing article titled "Galaxies in Collision" in the May issue of Sky & Tel, which should be out shortly (the digital version is already available).  It includes a number of interacting Arp pairs including the Antennae (cover photo) and other interesting duos such as the Mice, the Tadpole, the Heron, the Grasshopper and more.  Some of these are fairly well known and others are pretty obscure.  If anyone would like more "info" on the article, let me know.



7
Registration is open for the 2017 OzSky "Southern Spring" star party in Coonabarabran ("astronomy capital" of Australia), which runs from October 15-22 (7 nights).  If you have any interest in observing in the southern hemisphere check out http://www.ozsky.org/spring.asp.  That's me on the ladder of a 30" in SQM 21.8-21.9 skies.

I'm planning to attend again (this is my 8th trip to Australia!), as this is a remarkable opportunity to see the Magellanic Clouds and more.  All equipment is provided (mostly 18" to 30" scopes) -- you basically just have to show up and enjoy the dark skies.  A number of bay area amateurs have participating in OzSky star parties including Bob Douglas, Peter Natscher, David Cooper, Dennis Beckley, James Webster.  If anyone has any questions or possible interest, let me know.

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Observing Reports / Blazers, Seyferts, Double Rings from Lake Sonoma
« on: January 06, 2017, 12:42:18 PM »

On two consecutive Wednesdays (21st and 28th of December) I observed under clear skies at Lake Sonoma, located 30 miles north of Santa Rosa just above numerous Sonoma county vineyards -- this is the Lake just before crossing the bridge along Rockpile Road.

On both evenings we had small groups at the Lone Rock lot, in the hills above the lake (the photo was taken as I arrived on the 21st). The first Wednesday I was joined by Bob Douglas with his 28-inch f/3.7 Starstructure and Carter Scholz with a homemade 16-inch with Zambuto optics. Conditions were excellent - perfectly clear, fairly good transparency for this site (SQM readings hit 21.4 by 11:00 PM), perfectly calm with no dew. I returned on the 28th with Bob and we were joined by Mark Toney (20” Teeter Dob) along with a friend. Again we had perfectly clear skies with SQM readings in the 21.3-21.4 range and good seeing. Both nights we started observing around 6:30 and closed shop by 12:30 and over those 12 hours were very productive – I logged a total of 90 different objects in my 24-inch f/3.7 Starstructure. My observing list in included a mix of interacting and other unusual galaxies as well as a few galaxy groups and I’ve highlighted several of these below.

I started off both evenings by taking a look at the amazing blazar CTA 102, which at a redshift z = 1.037 has a light travel time of 8 billion years! Normally this quasar shines dimly at 17-17.5 magnitude, but is known to be an OVV — an Optically Violent Variable quasar. In the past couple of months it experienced a historic outburst reading reaching mag 12.7-12.8 when I took a look in November. It’s been fluctuating wildly in the past few weeks — on the 21st I logged it at mag 12.7 and was impressed that it was easily seen when I added an 8-inch aperture stop to my scope. But on the 28th it appeared at least a half-magnitude brighter than a nearby mag 11.7 star, so was certainly mag 11.1-11.3 and has now been glimpsed in down to a 50mm refractor. Wow!! When I later checked on the AAVSO web site, I found that several observers measured magnitudes in the 11.2 range, so my estimate was accurate. This latest incredible outburst is over 300 times brighter than its “rest” magnitude. I just noticed the Fermi Gamma-ray Space Telescope also recorded an outburst of 135 times its average gamma-ray flux on the 28th, making CTA 102 the brightest gamma-ray source in the sky.



NGC 309 + IC 1602
00 56 42.8 -09 54 50
V = 11.9; Size 3.0'x2.5'; Surf Br = 14.0; PA = 175°

This beautiful grand-design galaxy is one of the largest (diameter ~225,000 light years) and most luminous known spirals (absolute blue magnitude = -22.52). Even at a distance of 260-270 million light years it has a V mag of 11.9! In fact Arp used this galaxy as an example of a discordant redshift — he felt it was just too large for its redshift and mentioned that M81 could comfortably fit in between its gargantuan spiral arms. It also appears to be something of supernova factory, hosting 4 in the past 17 years: SN 2014ef, 2012dt, 2008cx and 1999ge.

In my 24” it was fairly faint but moderately large, roundish, fairly low but uneven surface brightness, contains a brighter core that increases somewhat to the center. I noted hints of spiral arms in the halo (slightly brighter arcs) — this was before viewing an image. A mag 12.5 star is 2’ NNE and mag 15 star is off the west side, 1.5' from center.

Nearby is IC 1602, which lies 13’ WSW. This galaxy is the brightest member of Abell Galaxy Cluster (AGC) 117 with a redshift-based (z = .055) distance of ~738 million light years. I noted IC 1602 as fairly faint, round, 20" diameter, slightly brighter nucleus. AGC 117 is one of the galaxy clusters in the Pisces-Cetus Supercluster, one of the largest known structures in the universe (see http://www.atlasoftheuniverse.com/superc/psccet.html)





Arp 54 = VV 453
02 24 00.9 -04 41 42
V = 14.2 / 15.9; Size = 1.0’x0.55’ / 0.4’x0.3’

Arp 54 is a little-known interacting pair at a distance of ~570 million light-years. It shows up in infrared surveys, as a radio source as well as an x-ray source, so it apparently is experiencing very vigorous star formation or perhaps has an obscured active galactic nucleus (AGN) — both signs of an interaction. Arp placed it in his classification of "Spiral galaxies with high surface brightness companion on arm”, though it doesn’t appear that the arm from the larger galaxy reaches the smaller galaxy. The edge-on to the south is not related to Arp 54.

Using 375x the larger galaxy (PGC 9113) appeared fairly faint, elongated 3:2 E-W, 30"x20", fairly low surface brightness, weak concentration. Its interacting companion PGC 9107 is just 0.9' WSW. It was a very small faint glow, only 12" diameter. Although it easily popped into view with averted I couldn't hold continuously. A mag 14.4 star is 0.5’ SW.





NGC 7805/7806 = Arp 112 = VV 226
00 01 28.4 +31 26 16
V = 13.3 / 13.5; Size 1.2’x0.9’ / 1.1’x0.8'; Surf Br = 13.2 / 13.2; PA = 47° / 20°

Arp 112 is an interacting triple system consisting of NGC 7805/7806, along with KUG 2359+311, a strange arc-like galaxy. NGC 7806, the galaxy in the middle of the image, is also a gravitationally disturbed system with a thin tidal tail to the north. It’s not known whether KUG 2359+311 (Kiso Ultraviolet Galaxy) is a pre-existing third galaxy or the remains of one of the other galaxies — it looks like a detached spiral arm to me.

Through my 24”, NGC 7805 appeared moderately bright (V = 13.3), fairly small, compact, very slightly elongated SW-NE, 25"x20", small bright core and even brighter stellar nucleus. Forms a similar pair with NGC 7806 just 50" NE. A mag 13.5 star is 1' west. Other than a different orientation, NGC 7806 (V = 13.3) is a visual twin of 7805. KUG 2359+311 was only marginally glimpsed in the 24-inch (V = 16.3), so I asked Bob Douglas if we could look at Arp 112 in his 28-inch. By bumping the power to 427x we were able to glimpse a small narrow glow in his scope.





Markarian 1018 = UGC 1597
02 06 16.0 -00 17 29
V = 13.9; Size = 1.0’x0.5’; PA = 0°

Visually, there’s nothing remarkable about this galaxy, which appears to be a coelesced merger of two galaxies. Using 432x I logged it as "fairly faint, slightly elongated N-S, 25"x20". Two 13th magnitude stars are 50" NW and 1.0' W and a mag 14.5 star is 1.0' ESE."

But astrophysically Mrk 1018 is quite unusual. It’s a Seyfert galaxy, a type of spiral with an active galactic nucleus powered by a massive black hole and whose spectrum contains emission lines from highly ionized gas. Type 1 Seyferts contain extremely broad optical emission lines indicating the nucleus contains hot gas near the accretion disc that’s moving/expanding at very high speeds. Type 2 Seyferts display only narrow emission lines, while Seyfert 1.5, 1.8 and 1.9 are intermediate cases. The two main classes are thought to reflect different activity levels of black hole feeding, though possibly the viewing angle of the accretion disc is a factor.

Historically, Mrk 1018 has been classified as a type 1.9 Seyfert. But in the 1980s, prominent broad lines appeared in the optical spectrum and it changed its classification to a Type 1 AGN. In 2006, though, it was announced that in the past five years Mrk 1018 has returned to its original state type 1.9 state (see https://arxiv.org/pdf/1609.04423v1.pdf). This second transition is thought to be due to a decrease in the black-hole accretion rate.





Arp 200 = NGC 1134 + UGC 2362
02 53 41.2 +13 00 53
V = 12.1; Size 2.5'x0.9'; Surf Br = 12.8; PA = 148°

Halton Arp placed NGC 1134 in his category of “Galaxies with material ejected from nuclei”. Probably he is referring to the “tidal plume” off the upper right end of the galaxy generally extending in the direction of UGC 2362, the chaotic blue galaxy to the west. These two galaxies have identical redshifts so likely experienced a “close encounter” in the past with the arm of NGC 1134 pulled out by gravitational tides.

At 375x NGC 1134 appeared fairly bright, elongated 2:1 or 5:2 NW-SE, ~1.2'x0.6', sharply concentrated with a bright core and fairly bright, sharp stellar nucleus. It was slightly brighter along the east edge with averted vision — probably the bright section of the eastern spiral arm on Rick Johnson’s image. A mag 13.6 star is 50" NE of center. UGC 2362, 7’ to the west, appeared faint, very low surface brightness patch ~20" diameter (probably the brighter central part of this Magellanic system). A mag 14.8 star is 0.8' S.





IC 1767
01 59 59.4 -11 04 44
Size 1.7'x0.6'; PA = 75°

At 375x I called this galaxy "fairly faint, moderately large, elongated 5:2 WSW-ENE, ~1.2'x.0.5', large brighter core, no sharp nucleus. The halo brightens slightly at the WSW edge - perhaps a knot in the galaxy?"

I was pleased when I checked later and found the PanSTARRS-1 image above clearly shows a small galaxy (identified as 2MASX J01595678-1104533 in NED), at the position I noted. Although this galaxy appears to be superimposed, I don’t know whether the companion is actually at the same distance (no published redshift) or possibly in front of IC 1767.





NGC 1713 group = LGG 120 = WBL 110
04 58 54.5 -00 29 20
V = 12.7; Size 1.4'x1.2'; Surf Br = 13.3; PA = 45°

NGC 1713 is the brightest in a loose galaxy group called LGG 120 or WBL 110 at roughly 200 million light years. The group includes NGC 1709 and several fainter UGC and CGCG galaxies. NGC 1713 appeared fairly bright, oval 4:3 SW-NE, 0.8'x0.6', gradually increases to the center. NGC 1709, just 2.7’ WNW, appeared fairly faint, elongated 4:3 SW-NE, ~0.4'x0.3', very small or stellar nucleus. A mag 12.3 star is 50" NW. The following members of the group were tracked down (offsets given with respect to NGC 1713). Only the two closest are shown on the SDSS image above.

CGCG 394-055, 7.7’ SW: Fairly faint, fairly small, slightly elongated ~N-S, ~20"x15", slightly brighter core. Forms a close pair with CGCG 394-056 1.3' NNE.

CGCG 394-056, 6.6’ S: Faint, very small, round, 12" diameter. A mag 13.5 star is attached at the southeast end. Mag 8.9 HD 31724 is 5' W.

UGC 3221, 24’ S: Fairly faint, thin edge-on 6:1 NNW-SSE, ~30"x5", even surface brightness. A mag 14.5 star is superimposed at the south end. A mag 9.2 star is 4.7' S as well as a nearby mag 9.9 star.

UGC 3214, 26’ NW: Moderately bright, fairly large edge-on 4:1 SW-NE, at least 1.6'x0.4'. Contains a bright, elongated bulging core and much fainter extensions.

CGCG 394-053, 21’ NNW: Fairly faint, fairly small, elongated 2:1 NW-SE, 30"x15”.





NGC 741 group
01 56 21.0 +05 37 44
V = 11.1; Size 3.0'x2.9'; Surf Br = 13.5

This group (called WBL 061) resides in Pisces at a distance of ~250 million light years and is dominated by the NGC 741/742 double system. NGC 741 has an unusually large halo, sometimes indicative of galactic cannibilism and if you look carefully there’s a small stellar like object immediately to the left of the nucleus of NGC 741. Perhaps a former companion that strayed too close and is now falling into the nucleus of NGC 741? NGC 741 has a extended X-ray halo reaching a distance of 19’ from its center. Furthermore, twin radio jets emerge from the nucleus of NGC 742 and spread into a larger lobe that encircles NGC 741.

Visually, NGC 741 appeared bright, moderately large, round, sharply concentrated with a small very bright core that increases to the center. The halo increases with averted to over 1’ diameter. A mag 11 star is 2.4' NW. NGC 742 is just 0.8' E of center at the edge of the halo at a projected separation of ~55,000 light years. This is a small galaxy but has a high surface brightness. It was moderately bright, round, 15” diameter. The following half-dozen galaxies are within 15’ of NGC 741 and share the same redshift.

CGCG 413-006 (often misidentified as IC 1751), 1.5’ NW: Fairly faint, very small, slightly elongated N-S, 0.3'x0.2', sharp stellar nucleus. The mag 11 star lies 1.4' W.

CGCG 413-002, 3.3’ SW: Fairly faint, very small, round, 12" diameter.

CGCG 413-001, 9.5’ NW: Very faint, very small, elongated ~2:1 ~E-W, 18"x9”. Once picked up could just hold continuously with careful averted vision.

CGCG 413-010, 11’ NNE: Faint, very small, irregularly round, ~15"x12".

UGC 1425, 12’ NE: Moderately bright, small, roundish, 18" diameter, high surface brightness, occasional sharp stellar nucleus. Increases a bit in size with averted.

UGC 1435, 15’ E: Faint, oval 3:2 SW-NE, 30"x20", very low surface brightness patch, no core or zones. Collinear with two 14th magnitude stars 2' and 3' E.





ESO 474-026 = Arp-Madore 0044-243
00 47 07.5 -24 22 14
V = 13.7; Size 1.2'x0.8'; PA = 175°

ESO 474-026 is a unique double-ringed galaxy with two perpendicular rings -- both an equatorial ring and a polar ring surrounding a central nearly spherical galaxy (the only component that was visible). It is thought to be have resulted from the major merger of two similar mass haloes. There is no nearby “hit and run” collider galaxy in the vicinity. ESO 474-026 is on a list of the most luminous galaxies (Cappi et al. 1998) and a strong source of far-infrared and CO emission. Its nuclear spectrum indicates active star formation.

Visually it appeared fairly faint, irregularly round, 25" diameter, very small bright nucleus with a stellar peak. The Redshift-based (z = .0527) distance is roughly 700 million years so I wasn’t expecting to see anything of the ring structures. But it was fun to contemplate this blazing beacon that shines at a relatively bright mag 13.7 over this vast distance.


9
Observing Reports / 8 billion light-year blazar ridiculously bright!
« on: December 29, 2016, 11:30:15 AM »
Last night (Wed, 12/28) we had a small group of 4 observers at Lake Sonoma including Bob Douglas (28" Starstructure), Mark Toney (20" Teeter dob) and my 24".

The highlight of the evening for me was the blazar CTA 102 (8 billion light years).  This is the 4th time I’ve taken a look — the first 3 times the magnitude was between 12.5 and 13.0, although I heard it had been acting erratically in the past week with some spikes in brightness.  Well, last night it was at least a half-magnitude brighter than a nearby mag 11.7 star, so certainly mag 11.1-11.3.  Wow!!  The "normal" magnitude of this quasar is roughly 17.5 so the latest outburst puts is over 300 times brighter.  I have never heard of ANY blazar this bright, let alone one this distant.  It's probably peaked and will decline after this point, but no one really knows.

We had excellent conditions -- perfectly clear skies in the SQM 21.3-21.4 range and good seeing.  I started getting cold and tired around 12:30 but at that point I had logged over 40 objects in 6 hours of observing.  Bye-bye, 2016!

10
Observing Intents / Lake Sonoma - Wednesday night! (28 Dec)
« on: December 27, 2016, 07:18:33 PM »
Sky conditions look excellent for Wednesday night.  I'll be at Lone Rock perhaps a half hour before sunset along with Bob Douglas.  Gotta check out the violently variable quasar CTA 102 again and catch some 8 billion year old light!

11
Observing Reports / Objects near and far at Lake Sonoma 12/21/16
« on: December 24, 2016, 11:32:35 AM »
On Wednesday night (21 Dec), I met up again with Bob Douglas (28-inch f/3.7 Starstructure) and Carter Scholz (homemade 16-inch with CZ optics) at our Lake Sonoma observing lot 30 miles north of Santa Rosa.  Conditions turned out to be excellent for this time of year - perfectly clear, good transparency (SQM readings hit 21.4 by 11:00 PM), perfectly calm and no dew at all.  At this time of year I was able to start by 6:30 and logged over 40 objects when I packed up at 12:30.

As we were waiting for the sky to fully darken, Carter noticed an iridium flare towards the north and later he saw a very bright satellite that initially we thought was the ISS.  It dimmed slowly like a satellite but headed in the wrong direction towards the southwest??  Later in the evening I was observing in Orion and noticed a slowly moving satellite in my field, which was tracking.  I knew immediately what this was -- a geosynchronous satellite -- and turned tracking immediately off so it would just sit there in the center of the field, while the stars zoomed by.  Very cool.

First on my agenda after seeing these naked-eye near-Earth objects was another look at the Blazar CTA 102, which was still in its mega-outburst mode at mag ~12.7 -- that's for a quasar at 8 billion light years. Easily seen even when I put an 8-inch mask on my scope.   In the middle part of the evening I focused on faint Arp galaxy pairs and logged 9 new ones in Cetus, Pisces, Aries, Eridanus and Orion.   I also observed two galaxy groups -- NGC 741 in Pisces (8 galaxies logged) and NGC 1713 with 5 galaxies.  I may put together an observing report later with more details.

I'm thinking of an encore session next Wednesday to end the year.

12
Observing Intents / OI - Lake Sonoma Wednesday night (12/21)
« on: December 19, 2016, 08:39:30 PM »
If the weather forecast holds, I plan to join Carter Scholz and Bob Douglas at Lake Sonoma (Lone Rock parking lot) on Wednesday night.  Should arrive around 4:30.

13
Observing Reports / Blazar burning bright and other goodies
« on: December 06, 2016, 09:46:46 AM »
Last Thursday night (December 1) I met with Dennis Beckley and Carter Scholz at Lake Sonoma, our “close-by” observing spot in the rural Sonoma County vineyards, about an hour and half drive from my house in Albany.  Carter was eager for first light on his new 16-inch Zambuto mirror and Dennis wanted to check out his new Greg Blandin Cross Bow Platform for his 18-inch Obsession.  Observing this time of year often comes with some compromise in terms of conditions.  We were fortunate to have clear skies, pretty good transparency, dry conditions (relatively low humidity) and no wind.  But seeing was subpar due to the jet stream and that restricted high power viewing.

Our first target for the night was the insane outburst of Blazar CTA 102, a quasar with a redshift of 1.037, implying a light-travel time of nearly 8 billion years.  This quasar has a normal quiescent brightness of 17th magnitude but it is known to go into outburst — so it is classified as an Optically Violent Variable (OVV) quasar.  It’s in the midst of a historically bright outburst —  as super-heated material spiral into the accretion disc surrounding the black hole, an intense magnetic field produces high-energy, relativistic plasma jets.  That jet happens to be pointed directly at us, so we are looking down the throat of the jet!   CTA 102 appeared marginally brighter than a mag 12.9 star on the AAVSO chart, so perhaps magnitude 12.7 or 12.8.  To see an object so relatively bright, whose light has been traveling some 8 billion years to reach us, is humbling.

A galaxy, NGC 7305, lies less than 6’ from the quasar.  It was easily seen as a fairly faint, 24” spot with a small bright core and diffuse halo.  At a distance of 360 million light years, this is not a nearby galaxy but still 22 times closer than the quasar.  It’s nice to get started observing so early this time.  By midnight I had observed already 5 hours and had logged 40 objects.  Here are some of my favorites.  Images are from the Sloan Digital Sky Survey (http://www.sdss.org)

— Steve Gottlieb

Abell Galaxy Cluster (AGC) 2626
23 36 30.3  +21 08 33

The 5 brightest members in the central region of AGC 2626 were viewed including IC 5336, 5337 and 5338.  This cluster lies in Pegasus at a redshift-based distance of nearly 750 million light years!

IC 5338 is the brightest and largest cluster member (cD class) in AGC 2626 and it forms a close pair with IC 5337, the second ranked member, just 1.3' W.   I logged IC 5338 as fairly faint, fairly small, round, 0.4' diameter, with a small brighter core/nucleus and a low surface brightness halo. IC 5537 appeared fairly faint, small, 20" diameter.  This is an edge-on with a length of 0.8', so I must have picked up only the middle section but it was comparable in surface brightness to the bright core of IC 5338.  Fainter IC 5336 (a close double system) lies 3.8' SW.  It was easily the dimmest of these three and seen only with averted vision as a very small, possibly elongated glow, 15" diameter.  This is a double system, but only one component was seen with confidence.  CGCG 455-028 was picked up 3.5’ SE of IC 5338 and noted as very faint, round, 12"-15" diameter, slightly brighter nucleus, low surface brightness.  A mag 12.7 star lies 1.3' SSW.  Finally, LEDA 1644527 was a tiny 10” knot 3.3' NW of IC 5338.



Arp 70 = VV 341
01 23 28.3 +30 47 04
V = 14.3;  Size 1.7'x0.6';  PA = 120°

Using 375x (about the highest power the seeing would allow), the brighter distorted spiral in Arp 70 appeared fairly faint, elongated 5:3 NW-SE, ~30"x18", broad concentration to center, no distinct nucleus.   It forms a close pair with VV 341b 0.8' SW.  The companion appeared very faint, very small, slightly elongated 12"x9".  Once identified, it could be held continuously.

Although Arp classified this system as a "Spiral with a small high surface brightness companion on arm", the stretched (tidal) northern arm of UGC 934, which hooks south towards VV 341b does not appear to reach the small galaxy.



Arp 128 = VV 205 = UGC 827
01 17 28.7 +14 42 12
Mag 15.4V + Mag 14.6V
Size: 0.6’x0.45’ + 0.6’x0.6’

Arp 128 is a close pair of overlapping and probably interacting galaxies.  Arp placed this pair in his classification group of "Elliptical and elliptical-like galaxies, close to and perturbing spirals.”  At 260x they were merged into a very faint glow elongated ~WNW-ESE, ~25"x15”.  At 375x the glow occasionally "resolved" into two clumps, either connected or within a common halo.  The 15" eastern clump was brighter and the 10" western component was extremely faint.  A 12" pair of mag 14/14.5 stars is 2.7' S and a mag 13.7 star is 2.4' NE.



CGCG 482-063 = PGC 7857
02 03 51.5 +25 55 31
Size 0.9'x0.7';  PA = 24d

Oh my, this galaxy is nearly lost in the glare of 5.7-magnitude 10 Arietis.  The first challenge is to split the bright star.  It’s a mag 5.8/7.9 pair at 1.2”.  With a two magnitude difference in brightness it’s a bit tough.  But I split it at 280x using an 8" mask on my scope.  The galaxy, though, required full aperture!

Using 225x and 260x it was visible as a fairly faint, round glow, ~20" diameter.  Although the surface brightness is surprisingly high, the view was improved with the glare of the star just outside the field, though the galaxy could still be easily seen with the bright star in the field.



WBL 102 = IC 329/330/331 triplet
03 32 02.9 +00 18 07
Mag 14.3V, 14.4V, 13.8V
Size: 0.9’x0.4’, 1.0’x0.3’, 0.9’x0.9'

There’s nothing special individually about these three IC galaxies in southwestern Taurus, a region you wouldn’t normally go galaxy hunting.  But check out the arrangement surrounding the 8th magnitude star!  Quite unique and perhaps worthy of a nickname.  The triplet was discovered French astronomer Stephane Javelle in 1891 while hunting for “nebulae” with the 30-inch refractor at the Nice Observatory.

IC 329 was fairly faint, slightly elongated, perhaps 20"x15”.  This one is situated 2' WSW of mag 8.3 HD 21926.  IC 331 is fairly similar and lies 2.6’ E of the star – fairly faint, round, very small bright nucleus.  Finally IC 330, 3.9’ N of the star, is fairly faint, very elongated WSW-ENE, 30"x10", small brighter core.  A mag 11.8 star is 1.4' NNE.



Markarian 331 (part of the HIPASS J2351+20 triplet)
23 51 26.8 +20 35 10
V = 13.9;  Size 0.7'x0.4';  Surf Br = 12.4;  PA = 146°

HIPASS J2351+20 (radio survey designation) is an interacting triplet featuring Markarian (Mrk) 331.  Mark 331 is a far infrared (FIR) luminous galaxy with an H II-like optical spectrum.  NED classifies it as a LIRG — that’s a Luminous Infrared Galaxy.  A LIRG emits one hundred billion times more far-infrared light than our sun does across the entire spectrum.  Apparently the huge infrared emission is from starburst activity, perhaps from the interaction.

Mrk 331 appeared moderately bright, compact, slightly elongated NW-SE, ~0.4'x0.3', small bright nucleus, with a fairly high surface brightness.  Much fainter UGC 12812 lies 2’ SW and required careful averted to glimpse.  It was seen as extremely faint, fairly small, elongated 3:1 NNW-SSE, very low even surface brightness. 



NGC 151
00 34 02.5 -09 42 20
V = 11.6;  Size 3.7'x1.7';  Surf Br = 13.4;  PA = 75°

This photogenic spiral in Cetus was discovered by William Herschel in 1785 with his workhorse 18.7” speculum reflector.  His notes read "pB, L, lE, lbM”, which translates to “pretty bright, large, little elongated, little brighter in the middle.”   The Carnegie Atlas of Galaxies describes the photographic appearance as follows: "The beautifully symmetrical grand design in the pattern of NGC 151 contains a smooth central bar which terminates at the place where two inner arms begin. The arms do not spring from the ends of the bar but start from two symmetrically placed points about 15° downstream from the termination of the bar - a common-enough feature...The two principal arms that start at these places relative to the bar, fragment as they move outward and form the multiple-arm pattern in which at least four arm segments can be traced on each side of the galaxy.”  Distance measurements place this galaxy at 150 million l.y.

Through my 24”, NGC 151 appeared bright, fairly large, with a very bright boxy rectangular central section that is slightly elongated NNW-SSE (this is the central bar and nucleus), encased by a fairly low surface brightness halo extended at least 2:1 E-W, ~2.7'x1.2'.  A mag 12.5 star is at or just off the ENE edge (1.7' from center). A superimposed companion (or is it a giant HII/star-forming region?) is at the tip of the eastern spiral arm of the galaxy, very close southwest of the mag 12.5 star.  It was marginally glimpsed but occasionally popped.

Here's a sketch of the galaxy by German amateur Uwe Grahn using a 16" in excellent conditions ---




NGC 722
01 54 47.1 +20 41 54
V = 13.5;  Size 1.7'x0.5';  Surf Br = 13.2;  PA = 138°

NGC 722 lies a mere 7' SSE from the glare of 2.7-magnitude Beta Aries!  This is a very similar situation as NGC 404 (“The Ghost of Mirach”) located 7’ from mag 2.1 Beta Andromeda.  But NGC 404 is magnitude 10.3V, while NGC 722 is magnitude 13.5V, so it’s a much tougher target!!

It was picked up immediately, though, as a fairly faint glow, elongated 3:2 NW-SE, ~30"x20", with a slightly brighter nucleus.  A group of mag 11.5-13 stars is nearby, including a mag 12 star 2.7' ENE.



UGC 122 = FGC 21
00 13 17.3 +17 01 48
V = 14.6;  Size 2.2'x0.3';  Surf Br = 14.4;  PA = 109°

UGC 122 is the 21st entry in the Flat Galaxy Catalogue (FGC).  The FGC consists of disk-like edge-on galaxies with a diameter of greater than 40” and a major to minor axis ratio of greater than 7:1.  In other words, flat galaxies!

This one was fairly challenging as it doesn’t have a brighter core and the surface brightness is low.  But even worse is the 12th magnitude star just off the west side, which severely hinders the view.  Using 260x it was seen as an extremely faint, thin edge-on 5:1 WNW-ESE, ~40"x8”.  Switching to 375x, I noticed a 16th mag star superimposed on the WNW end.


14
Observing Intents / OI - Lake Sonoma Thursday night (12/1)
« on: November 28, 2016, 03:26:35 PM »
I'm getting together with Carter Scholz and Dennis Beckley on Thursday night at Lake Sonoma (specifically, Lone Rock parking lot).  I plan to arrive around 4:30.  The weather forecast looks very good, though a bit nippy with a low of 38°.

Steve

15
Observing Reports / OR: Fall Galaxies through a 48-inch! (October new moon)
« on: November 23, 2016, 11:12:40 AM »
During the last new moon period (October 26-30) Howard Banich and I spent four nights (plus one clouded out) observing with Jimi Lowrey on his 48-inch in Fort Davis, Texas. His observatory is up the road from the Prude Ranch, the site of the Texas Star Party, and just down the road from McDonald Observatory on Mount Locke. A little background -- this zero expansion Astro-Sitall mirror is a 48.8 inch f/4 (4.8 inches thick) and even with 28 holes cored out of the back still weighs 715 lbs. No, the scope is not portable but still looks like a super-sized Dob. With a 16-foot focal length, viewing is often done up a serious climb on the ladder, but once you’re up there, the mesmerizing views suck you into the eyepiece and you’re not aware of the dizzying height.

With fairly long evenings, we covered scores of objects from bright showpieces such as NGC 253 and NGC 1365, to little known objects such as the recently discovered Pisces A and Pisces B dwarf galaxies http://www.sci-news.com/astronomy/hubble-dwarf-galaxies-pisces-04103.html. On the last night we were joined in the early evening by several guests including Steve Odewahn, a professional astronomer at McDonald, and the last PhD student of Gerard de Vaucouleurs, who devised the modern galaxy classification scheme. Steve starting off as an amateur, grinding and polishing the mirror for his first telescope and he enjoyed the views through the huge dobsonian. I took notes on exactly 150 individual objects over 4 nights, so the following objects, which include a few Arps, Hicksons and Shakhbazians, is just a small selection.

Most of the labeled images are from the Sloan Digital Sky Survey (http://www.sdss.org/) with identifications culled from NED (https://ned.ipac.caltech.edu/), HyperLeda (http://leda.univ-lyon1.fr/) and SIMBAD (http://simbad.u-strasbg.fr/simbad/).

Hickson Compact Group (HCG) designations are from Paul Hickson's list of 100 compact galaxy groups, published in 1982. A list of the better HCGs is at http://www.astronomy-mall.com/Adventures.In.Deep.Space/hicklist.htm, along with identification charts and descriptions. Many additional Arps are covered in detail at www.astronomy-mall.com/Adventures.In.Deep.Space/peculspr.htm. The Shakhbazian Compact Groups of Galaxies (Shkh) is a catalogue of 377 compact groups of compact galaxies found on the Palomar Sky Survey prints between 1973 and 1979 by Armenian astronomer Romela Shakhbazian. These galaxies are smaller and fainter than the HCGs and generally require at least an 18-inch to view. Finally, the complete Hickson and Arp catalogues can be downloaded in Excel format at http://www.astronomy-mall.com/Adventures.In.Deep.Space/catalogs.htm.

-- Steve Gottlieb

NGC 278
00 52 04.3 +47 33 02
V = 10.8; Size 2.1'x2.0'; Surf Br = 12.2

NGC 278 is high surface brightness spiral in Cassiopeia. Although face-on, it’s difficult to distinguish the individual arms as the dust lanes seems to snake across the galaxy slicing them into thick sections. We used 610x and 813x to try and resolve structure. The galaxy was extremely bright, large, with a squarish halo ~1.4' diameter. The center was very well concentrated with an intense round core that increases to the center. Sections of the two main thick spiral arms were visible, particularly along the north and south portion of the halo. Slightly darker lanes outline the inside of the arms. The inner arm sections are only noticed as subtle brighter patches. A well defined, small knot is on the east side of the halo [25" from center] and a second small knot is on the northeast side [23" from center]. These two star-forming complexes are catalogued as X-ray sources in NED. I also noted a third object at the NE edge, but at this position on the HST image is a very faint star.




Arp 290 = IC 195 and IC 196
02 03 47.1 +14 43 26
V = 13.0 and 12.9; Size 1.5’ x 0.5’ and 2.8’ x 1.4’

Halton Arp placed this double system in his category of “Wind Effects”. This refers to the diffuse tidal plumes seen in IC 196, the larger member of the pair. These galaxies lie in Aries at a distance of roughly 155 million l.y. The small galaxy LEDA 212903 just to the north of IC 196 is not part of the interaction and lies far in the background.

Using 488x and 610x, IC 196 appeared bright, large, very elongated but irregular 5:1 ~N-S, ~2.0'x0.4', well concentrated with a small, round bright core. A fairly thin long arm or tail extends due south from the core and then curls southwest towards IC 195. It appears to spread out and dim on the southwest end [0.9' from center]. A shorter arm extends north from the core ~30" and dims abruptly. But a very low surface brightness, elongated N-S patch is detached on the northern end (part of an outer tidal tail or loop) ~1' from the center. The apparent companion LEDA 212903 is just northeast of this patch and visible as a small faint glow, elongated 3:2 N-S, ~15"x9”.

IC 195 is fairly bright, moderately large, sharply concentrated with a bright, elongated 2:1 core NNW-SSE and highlighted by a stellar nucleus. The halo or spiral arms are very low surface brightness and extend 5:2 NW-SE, ~1.0'x0.4'. A distracting 15" pair of mag 10.4/12.7 stars lies 2.3' W.




Arp 284 = NGC 7714 and NGC 7715
23 36 18 +02 09 21
V = 12.5 and 14.2; Size 1.9’ x 1.4’ and 2.6’ x 0.5’

Arp 284 is a pair of interacting galaxies NGC 7715 and NGC 7714 in Pisces at a distance of ~100 million light years. Arp classified these in his category "infall and attraction”, probably referring to the tidal bridge seemingly connecting NGC 7715 with NGC 7714. John Herschel discovered NGC 7714 with his 18-inch speculum reflector, but missed the dimmer companion NGC 7715 just east. It was found by Lord Rosse in 1850 with the 72-inch Leviathan.

Using 610x, NGC 7714 appeared very bright, moderately large, with an unusual irregular structure, ~1.2' diameter. This deformed, interacting Wolf-Rayet galaxy is dominated by an extremely bright stellar nucleus (starburst activity). A short bar-like central region is elongated NNW-SSE. A curved arm bends sharply west on the south end of the "bar" and contains a very small knot (southwest of the nucleus). A second arm, which appears to consist of a series of HII knots on the SDSS, begins on the northwest end of the "bar" and extends a short distance northeast. A low surface brightness halo appears as a hazy glow on the eastern side only [a tidal loop on the SDSS]. The western tidally stretched arm of NGC 7715 2' E heads towards NGC 7714 but doesn't form a complete bridge. NGC 7714 is located just 4' NW of mag 5.7 16 Psc and the bright star needs to be kept out of the field.

NGC 7715 is fairly bright, moderately large, thin edge-on 6:1 WSW-ENE. This distorted galaxy is dominated by a small, bright elongated core ~20"x8" that increases to a star-like nucleus. Long stretched tidal arms or plumes extend WSW-ENE, ~1.8'x0.3'. The western "arm" heads towards the center of NGC 7714, but dims out just before reaching the halo.




Shakhbazian 84
23 34 38 +07 59.6
Total diameter 1.2'

Armenian (female) astronomers Romela Shakhbazian and Mina Petrosian discovered a number of compact groups of compact galaxies in the 1970’s. Shakhbazian 84 is a faint quartet spanning only 1.2' in a north-south curving chain. The members are roughly equally spaced. The group is ~5' NE of a mag 9.4 star and ~1' NE of a mag 14 star. I could only find the redshift on a single member (z = .062), with a light-travel time of ~834 million years.

The group was examined at 610x and 813x. From north to south here are my notes.
Shkh 84-2: faint to fairly faint, small, slightly elongated ~E-W, ~18"x15". A mag 17.9 star is 15" NW.
Shkh 84-3: faint, small, round, 15" diameter.
Shkh 84-1: faint to fairly faint, small, round, 15", small brighter nucleus. A mag 14 star is 1' SW.
Shkh 84-6: faintest of four and noticed only at 813x. It appeared extremely faint and small, slightly elongated, perhaps 9"x6".




NGC 864
02 15 27.8 +06 00 09
V = 10.9; Size 4.7'x3.5'; Surf Br = 13.8; PA = 20°

Unfortunately, this striking two-armed barred spiral has a bright mag 10.7 star superimposed on the east side [44" ESE of center]. Even with this distraction it appeared bright, fairly large, elongated 3:3 SW-NE, well concentrated with a bright core. The core extends into a weakly defined bar WNW-ESE. A long thin spiral arm is attached to the west end of the bar and it curls gradually counter-clockwise to the south for nearly 90°, ending due south of the core [separation 1.2']. The second spiral arm is not as easily seen as it begins just inside (west) of the bright star, which detracts from the view. This thin arm extends straight north, roughly at a right angle to the bar and merges into the halo on the northeast side. UGC 1775 = Arp 10 is 49' SE.




Hickson 94 (includes Arp 170 = NGC 7578A and NGC 7578B)
23 17 13 +18 42 16
V = 14.1 to 17.2

NGC 7578 = Arp 170 = HCG 94A and 94B is located within the Great Square of Pegasus at the west edge of the rich cluster Abell 2572. It lies at a redshift-based distance of ~550 million l.y. Arp classed it under galaxies with diffuse counter-tails, referring to the diffuse spread of gas and stars to the south of the pair. Hickson catalogued a septet (94A through 94G), all at a similar distance. A 16-inch with reveal 3 of the members, but the entire group was visible in the 48-inch.

At 488x, NGC 7578B = HCG 94A was a fairly small prominent glow, sharply concentrated with a very bright core that gradually increased to the center and a low surface brightness halo ~30” diameter. A mag 14.5 star is at the NE edge [17" from center]. HCG 94A forms a bright double system with NGC 7578A = HCG 94B 0.6' SW. The companion appeared fairly bright (V = 14.2), small, round, sharply concentrated with a very bright core increasing to small intense nucleus. HCG 94D is faint to fairly faint (V = 16.1), very small, round, 8" diameter, even surface brightness.

HCG 94C, the third brightest (V = 15.1) and perhaps the largest in the septet, is 2.2' NE. It appeared moderately bright and large, very elongated at least 3:1 NNW-SSE, ~30"x10", well concentrated with a sharp bright nucleus. HCG 94F, just 0.5' NW, is very faint (V = 17.0), very small, slightly elongated, 8"x6". HCG 94G, 0.9' N of HCG 94C, is an extremely small, very faint glow (V = 17.2), only 6" diameter. Completing the septet is HCG 94E, 1.2' NNE of NGC 7578. This extremely faint (V = 16.9) edge-on extends 0.4'x0.1' and has a very low even surface brightness. The observation was made through thin clouds.




NGC 7448 = Arp 13
23 00 03.6 +15 58 49
V = 11.7; Size 2.7'x1.2'; Surf Br = 12.9; PA = 170°

Halton Arp placed this galaxy in his category "Spiral galaxy with detached segments”. The “detached segments” likely refer to the bright blue-green OB associations and HII regions in the SDSS image above.

A 610x I found a very bright oval ~2:1 N-S, with knotty structure. The central portion is brighter along the major axis like a weak bar and in the center is a small, very bright nucleus. A bright, prominent knot, 10"-12" diameter, is just west of the northern tip of the galaxy and a weak knot is close east [by ~15"]. The northern half of the galaxy is generally brighter with a slightly mottled surface. The galaxy has a weak enhancement along the southwest edge of the halo [spiral arm] and a fairly faint knot is on the southeast side [40" SE of center]. Overall, the southern part of the halo has a lower, more uniform surface brightness.




Hickson 18 = Arp 258 = VV 143 (UGC 2140)
02 39 06 +18 23

Halton Arp classified the irregular blue mess as "Galaxies with Irregular clumps”. Hickson considered it a quartet with a single galaxy (HCG 18A) and an interconnected triplet (HCG 18B, 18C and 18D), also known as UGC 2140. Although Hickson assumed these were interacting or merging galaxies, a recent study suggests this is a single highly irregular galaxy with several knots. Furthermore, HCG 18A has a redshift of z = .034, two and a half times that of UGC 2140, so it lies far in the background at a light-travel time of ~460 million years. As a result, there is no compact group here as Hickson assumed.

HCG 18D is the northwest component of the UGC 2140 chain and contains a fairly faint, very small knot, 6"-8". This knot is embedded in a low surface brightness glow extending to the southeast and containing 18C and 18B. Very faint haze bulges out just east of HCG 18B. HCG 18C is the central component of UGC 2140. Its nucleus appeared faint, very small, ~9"x6" and is surrounded by low surface extensions to the northwest and southeast, merging into HCG 18B on the southeast end. HCG 18B is fairly faint, very elongated 3:1 or 4:1 NNW-SSE, perhaps 45"x12". This portion of UGC 2140 is a similar to size as HCG 18A but has a fairly uniform surface brightness. A mag 15.5-16 star lies 0.6' E. HCG 18A, centered about 1.5’ SE, appeared moderately bright and large, very elongated 7:2 WNW-ESE, ~40"x12", small brighter core.




NGC 7436 Group = VV 84
22 57 57.5 +26 09 00
V = 13.0; Size 2.0'x2.0'

NGC 7436 is the brightest of 8 galaxies swarming nearby within a 4’ circle, including a very tight knot of NGC 7436, 7436A, 7431 and 7435. NGC 7436 appears to have an engorged halo, perhaps from previously snacking on some nearby companions that wandered too close. I seen the entire group in my 24” with some effort, but in the 48-inch they were all easy targets.

Using 610x NGC 7436 appeared bright, moderately large, round, sharply concentrated with a very bright small core, increasing to a stellar nucleus. The halo has a much lower surface brightness and contains NGC 7436B, which pokes out of the halo on the west side. The contact companion appeared moderately bright, fairly small, very elongated 3:1 E-W, 24"x8", very small bright nucleus.

NGC 7435, off the southwest side of the halo, is fairly bright, elongated 5:2 NNW-SSE, 30"x12", small brighter nucleus. A mag 15 star is on the NNW end [17" from center]. NGC 7433, about 1.5’ NW of NGC 7436, is moderately bright, elongated 5:2 SW-NE, 35"x14", brighter nucleus. PGC 70122, another close companion to the SE is fairly faint (V = 15.7), small, round, 15" diameter. LEDA 1763039 to the south is moderately bright (V = 15.3), fairly small, round, 15" diameter, fairly high surface brightness. A mag 16 star is 20" E. Finally LEDA 1766408 to the north is fairly faint (V = 15.9), slightly elongated SSW-NNE, ~15"x11".




NGC 253 and companions
00 47 33.1 -25 17 17
V = 7.2; Size 27.5’x6.8’; Surf Br = 12.7; PA = 52°

I've viewed NGC 253 a number of times in the 48-inch and the view is always jaw-dropping as the mottled galaxy explodes into numerous bright knots, dusty patches, dark lanes and luminous star associations. These notes were from a previous view, as we were focused on the small companions to NGC 253 indicated above.

Using a 21mm Ethos (232x), NGC 253 completely filled the 26' field. The central region of this starburst galaxy contains a blazing, nonstellar nucleus surrounding by an intense, elongated core with several bright patches around the periphery of the core (segments of the inner spiral arms). Just northwest and southeast of the nucleus are extremely bright sections of the core. Since the galaxy is only 12° from edge-on, many visible features extend parallel to the SW-NE major axis (PA = 52°).

A dark lane running SW-NE parallels the core just off its northern side. Close northwest and parallel to this dust lane is a very bright, fairly narrow arm, extending ~3' in length. Another thin arm (also running SW-NE) is to the southeast of the core with a prominent, very thin section ~3.5' SW of center, just southwest of a superimposed mag 12.5-13 star. Three smaller bright patches surround a superimposed star ~2.5' NE of the nucleus. The brightest and largest of these patches is close southeast of the star. Further northeast the surface brightness lowers in the outer portion of the galaxy, but it still appears curdled and blotchy. Several bright stars are near the periphery including a mag 9.3 star 6.2' SW of center and a mag 11.6 star 3.8' W of center. A brighter patch is ~3.5' WSW of center is near the latter star. Additional luminous patches are further out on the southwest end.

Four labeled small galaxies were tracked down. One (labeled [BGK2008] S72) is situated along the southern edge of the galaxy, just 4.5' SSW of center! It appeared fairly faint, very small, round, 12" diameter. Is this a dwarf companion to NGC 253 or a background galaxy that happens to lie on the same line of sight. Unfortunately, there is no available redshift I could find to settle this question.

Another companion is LEDA 198197, situated 15' NE of the center of NGC 253, ~3' beyond the northeast end of the galaxy. It was an easy target in the big scope, noted as "fairly faint, elongated 3:2 SW-NE, ~21"x14", small brighter core. Within a N-S string of stars with a mag 14 star 1' N and a similar star 1' SE.” I was surprised to find this object has a redshift of z = .064, which implies a light-travel time of ~860 million years. Furthermore, although we only saw a single glow, it's actually an interesting overlapping pair!

LEDA 198197 has been the focus of studies with both the Hubble Space Telescope (HST) and the Very Large Telescope (VLT) at Paranal. First was a 2008 study titled "An Extended Dust Disk in a Spiral Galaxy: An Occulting Galaxy Pair in the ACS Nearby Galaxy Survey Treasury" (https://arxiv.org/pdf/0810.2646v1.pdf). The abstract mentions "The foreground disk system (at z = 0.06) shows a dusty disk much more extended than the starlight, with spiral lanes seen in extinction out to 1.5 * radius, approximately 6 half-light radii. This pair is the first where extinction can be mapped reliably out to this distance from the center."

Here’s the HST image of the overlapping pair LEDA 198197



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