Author Topic: Late report on Dino 12/1  (Read 1332 times)

mccarthymark

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Late report on Dino 12/1
« on: December 13, 2016, 04:31:20 PM »
It’s been a while since this session but I finally had some time to do a write up of the visit to Dino on 12/1.

As we waited for dark we were able to pick out Mercury a couple degrees above the horizon, with binoculars (thanks to George for finding it). It formed a long line with Venus and Mars, all about the same distance apart. A very picturesque scene along with the two-day old moon, round with earthshine.  A while later we saw the ISS pass. Joe Bob happened to see it rising from the western horizon. We watched as it rose and were excited to see it transit the earthshine part of the moon. The others began to track it with their binoculars, wondering if they could see any structure. I decided to try tracking it with the 10-inch f3.8 @ 37x, and I was able to fairly easily. It was bright, but appeared boxy. It was very cool to see it barreling through fields of stars -- it was headed for zenith and the Cassiopeia Milky Way region. As it passed zenith it began to slowly dim, and eventually I saw it as a small orange tube. I kept on it as it grew fainter, still able to track it easily with the Springsonian, even as it became fainter than most of the stars. Eventually it disappeared, and my telescope was pointed about 15° from level.

I didn't have any specific plan for observing, and I made few notes. SQML was 21.18, a little low.  While it was a chilly 40°F, there was no dew, and I had dressed for the weather anyhow. I knew I wanted to exploit the scope's wide FOV and to try large scale objects.

I saw Blanco 1, which I wanted to see as a whole for a long time. It was a disappointing, large loose cluster of a dozen or more stars in a triangle pattern. Meh. I started out with this object thinking I would go to the Sculptor Dwarf and then the Fornax Dwarf, but the light dome from the Los Banos Reservoir lights washed out the horizon to 15°. There were light domes all around, sadly. So I abandoned the lower elevations and went high.

George suggested I try the Helix nebula.  He shared the view in his 13-inch, and showed me a good way to find it with a reflex sight: make a right triangle with Fomalhaut and Skat (Delta Aquarius). I found it straight off.  It looked nice with a UHC -- annular, with a large darker round interior.

My next thought was to try IC 342, the notoriously difficult face-on spiral in Camelopardalis. I wanted to start from Kembel's Cascade, an asterism in lower Camelopardalis near Cassiopeia. After some checking of my charts I did succeed in finding the straight line of stars making the asterism, and the small open cluster NGC 1502 at the end of it. Some nice colorful stars in the field. I then carefully star hopped through the eyepiece up the few degrees north to IC 342. I immediately saw an oval glow behind a rather dense field of stars -- if wasn't sure of my star hop I would have assumed this was an open cluster. It was the galaxy's relatively bright small core and nucleus. The arms were not apparent; there was a very subtle change in grayscale around the relatively brighter haze, but nothing certain.  It was like looking for a soluble fish.  I want to try this one again with the 20-inch to see if I can discern any arms.

I did some lazy sweeping around the Milky Way. The North America Nebula filled more than the field, and was billowy and cloud-like. I could see a large chunk of nebulosity hooking away from Mexico to the east. The Pelican Nebula (IC 5067 & 5070) was large and almost bright. And I could see the three condensations beneath the Pelican (IC 5068). The Gamma Cygni area was turbulent with nebulae and dark nebulae, too much for me to describe well. Same with the Mu Cephei area (IC 1396 etc.). And the Flaming Star Nebula (IC 405) -- which was quite astonishing. IC 405 appeared as a wide comma, with IC 410 on the other side of the bright elongated star cluster Mel 31. M38 looked great, and I could see the small faint cluster NGC 1907 at its rim, not unlike the small cluster at the edge of M35.  It was very special to try some comet sweeping, coming across clusters, asterisms, vacancies and crowds of stars in the sky.

I shared a view of the California Nebula (NGC 1499) with the others, with an H-beta filter. In this scope it appears large, bright, with many tendrils. It does not quite fit in the field -- panning east or west reveals the thinly tapering ends. So far this is my favorite object to view in this scope.

Around 11pm I happened to take a rest from the eyepiece and looked up.  I noticed a bright white flash and assumed it was a plane.  I watched it for a minute.  It flashed again but this time it was dimmer, more yellow.  And it seemed to be moving more slowly than a plane would.  Then again the bright flash -- I was sure it was a satellite.  So I asked Jamie and Peter to take a look.  We were wowed by the bright flashes, which came in irregular intervals.  We believed it to be a tumbling satellite or space debris; it was moving below the "W" of Cassiopeia roughly west to east.  I tried to find out what it was next day at the Heaven's Above website, but don't find any matches.

Near midnight some thin clouds moved in from the north. It was time to pack up, but I wanted some more looks through the scope – who knew the next time there would be clear weather? I took a quick look at the Flame Nebula (NGC 2024) which was very distinct, even with Alnitak in view. We tried the Horsehead (B33/IC 434), which we could see as a dark thumbprint -- but not very well. I tried for the Witch Head Nebula but only suspected some grayscale changes -- needs a darker and more transparent sky. Finally, George wanted to see M81/M82, so we pointed the scope up there. It was just seen at the edge of some clouds. I could see NGC 3077 hiding out next to a nearby star. Very nice view of the trio and a nice way to end the night.
Mark

DDK

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Re: Late report on Dino 12/1
« Reply #1 on: December 13, 2016, 09:41:04 PM »
We had a fun night, didn't we.
Was looking at IC 410 and NGC 1893 a year ago from that same spot. Along with being pretty, they're an interesting set as well. 410 is lit up by the UV of that bright cluster, which is only about a million years old. Both emission nebula and young cluster are in the Perseus Arm, next one out from our Orion Arm. They're both around 13,000 lightyears from here. So that cluster is intrinsically amazingly bright, and the nebula is vast. Figure ca 9x farther away than the Belt, M42 and the Flame.
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sgottlieb

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Re: Late report on Dino 12/1
« Reply #2 on: December 14, 2016, 02:01:40 PM »
I've seen Blanco 1 undeservedly on lists of the top open clusters -- purely based on magnitude (listed at V = 4.5), not on visual appearance.  In fact, Zeta Sculptor, which is the brightest star within the confines of the cluster, is apparently not a member based on its Hipparcos proper motion.  But it does have one interesting feature -- its galactic latitude is nearly -80°, so only 10° from the galactic south pole.  Not a place you'd expect to find an open cluster.

In any case, here's my small telescope report from 5 years back...

This very large scattered group following 5th magnitude Zeta Sculptoris was very nice in the 80mm finder at 13x and 25x.  A 25' string of stars oriented WNW-ESE is on the south side including 7th magnitude HD 225187 at the WNW end of the string.  Four of the brightest stars are north of this string including mag 6.4 HD 225200 at the north end.  Extending the string to the WNW leads to Zeta, which is isolated from the other brighter stars."

DDK

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Re: Late report on Dino 12/1
« Reply #3 on: December 27, 2016, 07:28:08 PM »
I took a turn and went for Blanco 1 on the solstice night at the Pinnacles last Wednesday. Strange object, I used the 10x50 binocs to catch it. Counted 20 stars in a broad triangle over 1° across. Sky Atlas Companion in fact lists its diameter as 90'.

Part of what makes it look so bloated from here is that it's actually close, at 815 ly. Still, that cluster sure dispersed quickly, being relatively young at 50 million years. The Hyades are 151 ly away by comparison; Berenices's Hair (Melotte 111) is about 280 ly away and 9x as old as Blanco 1, at 450 million years, but a third as far away, and over 5x the apparent size, ca 7.5°.

50 million years, the age of Blanco 1, kept running around in the back of my head. Those hoodoos at the Pinnacles we were looking at, the core of the old volcano, are 100 million years old, twice as old as that cluster of stars.
World without end.
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DDK

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Re: Late report on Dino 12/1
« Reply #4 on: January 01, 2017, 04:15:01 PM »
Nope. Still world without end, but I should have listened to that little voice. The Pinnacles aren't 100 million years old, which would put them even with the Appalachians, but 10 million, like the Himalayas. Much younger, and far younger than those stars in Blanco 1. Please allow the correction.
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mccarthymark

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Re: Late report on Dino 12/1
« Reply #5 on: January 01, 2017, 06:37:38 PM »
Allowed.  Thanks for the background on the object.  It--and so much more besides--deserves more than the "meh" I so callously gave it.
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Re: Late report on Dino 12/1
« Reply #6 on: January 01, 2017, 10:11:50 PM »
It's one of those objects that is actually pretty meh to look at, and fascinating for what it is. There's that ancient open cluster way up north, ngc 188 in Cepheus, that looks all reddened and old and kind of dim. Turns out it's just too old to be an open cluster, and it's red because all the stars we see in it are in a slow endgame, red giants. Some 8-10 billion years old, according to Brent Archinal.
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Mark

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Re: Late report on Dino 12/1
« Reply #7 on: January 02, 2017, 08:21:59 AM »
... ngc 188 in Cepheus <snip> ... it's just too old to be an open cluster <snip> according to Brent Archinal.

Hey Jamie ... I assume that's in the book on open clusters by Archinal?
http://www.willbell.com/HANDBOOK/starclusters/index.htm

Every reference I find says open (galactic) cluster.  Here's a recent one, 2014:
http://onlinelibrary.wiley.com/doi/10.1002/asna.201312112/abstract




DDK

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Re: Late report on Dino 12/1
« Reply #8 on: January 02, 2017, 01:30:02 PM »
Sorry Mark, I was being sardonic. Sure every source says 188 is an OC. It's old enough though that no one has a model for how it's stayed together this long. Tidal forces should have separated those stars long ago. And yeah Archinal's book is where I went for the age.

Figure you, Wags, know all this, but here goes for the Lurkers. I pulled out Archinal's book, because different reliable books give widely different ages for 188: Sky Atlas Companion says 5 billion years, Burnham's says 12-14. Figure Archinal's number is the best I can put my hands on, he goes to the middle at 8-10 billion years old.

Compare the cluster our Sun was born in, 4.5 billion years ago, that's widely dispersed, long since.
Here's a good place to plug Brent Archinal's Star Clusters. What a resource, authoritative, by one of the few professional astronomers who's an observer as well. Interesting chapters, and useful charts. Fun reading.
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Mark

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Re: Late report on Dino 12/1
« Reply #9 on: January 02, 2017, 02:37:32 PM »
Sorry Mark, I was being sardonic.

Well, thanks.  That helps.  To be sure I was understanding your meaning, I double checked the definition of sardonic, and chuckled to read this example of its use:  "His sardonicism was getting on my nerves."  Good word! ;-)

I offered NGC 188 as a challenge object in some writing recently - I mentioned its age, and position too....