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Topics - Mark

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TAC Visual / Look at Moon and Jupiter now!
« on: June 03, 2017, 08:48:11 PM »
If you're not checking it out, you should be!

Shadow transit too!

Venus at mag -4.29 0.7 AU away, and Uranus at mag 5.88 20.6 AU away, in one wide field of view.  10 magnitude difference!  Interesting, Starry Night Pro shows Venus maximum magnitude from Earth as -7.08.  Really?  Maybe it means something else.

Venus will have 50% illumination, 24 arc-second size.  Uranus will be 3.4 arc-seconds.

Observing Intents / New Moon weekend
« on: April 17, 2017, 06:17:24 PM »
Anyone notice the weather forecast?  Shhhh....  :P

Thinking Pinnacles, Saturday night....

TAC Visual / Question about observing at Pinnacles
« on: April 12, 2017, 10:55:52 PM »
Is it possible to catch some sleep in a car after observing at Pinnacles west?

Thanks for any help.

TAC Visual / Comets....
« on: April 12, 2017, 11:20:20 AM »
Anyone been checking out the comets?  At least three I know of currently, all are reasonable mags.  Here's where Comet Johnson (mag 8.2 and brightening in Hercules) is going to be on the 27th, close to Phi Herculis.  The nice sketch is from Cloudy Nights in a 12.5" telescope.

Comet 41P/Tuttle-Giacobini-Kresak is also an easy find, this chart showing it on the 21st just off beta Draconis, mag 8.7 but forecast to dim (this comet is famous for outburst though).

Nice comet site, with excellent graphics and current info:

TAC Visual / Nice binocular double star
« on: March 29, 2017, 10:38:32 AM »
Was looking through the good old Night Sky Observers Guide last night, curious about double stars in Cygnus - I am out before dawn these days and Cygnus is up high then.

I came across 61 Cygni, aka Struve 2758.  Its a wide double, 30.3" separation, which makes it good for binoculars.  Its the color I'm really interested in seeing - here's the description from the book:

"61 Cygni, a wide, easy separated double of two orange K-type dwarfs, is only 11.2 light years distant, the twelfth nearest star or star pair to the Solar System.  The two stars orbit each other in a period of 650 years, and will achieve maximum separation, 34", bout 2100 A.D.  The components have luminosities of only 8% and 4% of the Sun's.  Their color is probably at its best in binoculars, with which both stars are a stunning chrome orange-red.

4-6" Scopes - 75x: An easy target for small telescopes, 61 Cygni is a wide pair of bright orange stars."

Its easy to find, just off Tau Cygni behind the western wing.  Anyone seen this double?

Annual Star Parties / Monday Morning Memory....
« on: March 27, 2017, 09:40:49 AM »
We've come a long way....

TAC Visual / Double Star Epsilon Canis Majoris
« on: March 03, 2017, 11:29:21 AM »
I was looking at my old AstroCards, for good double stars in Canis Major.  I saw Epsilon listed, mags 1.6 and 8.1 with a 7.4" separation.  Started looking for any reports of splitting it - don't find any. 

Wikipedia says "The +7.5 magnitude companion star is at 7.5" away with a position angle of 161° of the main star. Despite the relatively large angular distance the components can only be resolved in large telescopes..."

Anyone try this?  I am somewhat surprised at what I'm reading....

I am selling the Gran Turismo I bought several years ago, which I've used only twice.  Here is AP's current info on this telescope:

Price is $7,300.   Telescope, 2.7" focuser, covers, carrying case, 4.7" mounting rings.

Great scope visually, terrific for imagers - just in time for the Big Eclipse....  Little know about this telescope, Jay Reynolds Freeman, long time TACo, now at SpaceX, suggested the name Gran Turismo to Roland Christen - a tie to TAC.

I'm in the bay area near SF.  Contact me if interested.


TAC Visual / Moon and Venus right now!
« on: February 28, 2017, 06:27:17 PM »

Rants and Off Topic / Happy Birthday Jamie Dillon
« on: February 21, 2017, 08:57:03 AM »
To one of TAC's longest shining stars -

Best wishes old soul.  Here's to another great trip for you around our old Sol.


TAC Visual / Venus, Moon and Mars together tonight.
« on: January 31, 2017, 06:44:51 AM »
Tonight the waxing crescent Moon is 2-2/3rd degrees below Mars and just over six degrees from Venus next to the Circlet of Pisces and between Diphda in Cetus, and Markab in Pegasus.  Mars is magnitude 1.11, Venus at -4.56, and the moon an 18% illuminated waxing crescent at -10.95.

Courtesy Orion Telescopes and Binoculars"

TAC Visual / Blast from the Past
« on: January 30, 2017, 08:43:34 AM »
Came across this old photo, from a couple years back.  Sure fun gathering around the dearly departed Dobzilla, at Willow Springs.  Although the scope may be gone, the location survives.  I think a group went there this past weekend - maybe we'll get a few ORs posted from there.  Another nice locations just up the road is Bob Ayers' place.  All private property, and about dark as it gets near the Bay Area.

Will have to choose between February new moon and a big hike at Pinnacles, but feeling fired up to get back out again!


Rants and Off Topic / GSSP Anniversary
« on: January 24, 2017, 07:34:56 AM »
Opening of this year's registration got me wondering what anniversary this year will be, for the various incarnations of GSSP.

One TACO with history tells me, the Original Six did an exploratorytrip to Mount Lassen summer of 1993, and first Lassen Star Party followed in 1994.  Grandaddy of GSSP.

So, next year will be the 25th Anniversary?  Mind-numbing.

Trivia - who were the Original Six?

Eli Rykoff, KIPAC
SLAC National Accelerator Laboratory

Tuesday, Jan. 31, 2017 at 7:30 PM

Panofsky Auditorium
Science and User Support Building (BLDG 53)

The distribution of galaxies in the universe is patchy. Galaxies are bound together in clusters made of stars, hot gas and invisible dark matter. These galaxy clusters are part of a cosmic web of filaments, nodes and empty voids that has been building up over 13 billion years. How do we observe this structure, and how do we use gravitational lensing and satellite X-ray observations to measure its mass? How do galaxy clusters trace the past expansion of the universe and reveal our future? This lecture will highlight data from the Dark Energy Survey, today’s largest cosmic survey, to answer these questions.

SLAC Research Scientist Eli Rykoff has been weighing the universe for over a decade. He received his PhD from the University of Michigan in 2005, where he built a worldwide network of automated telescopes for following gamma-ray bursts, the most energetic explosions in the universe. After graduating, he transitioned to studying galaxy clusters, which evolve over billions of years rather than fractions of seconds, and did postdoctoral research at the University of California, Santa Barbara and Lawrence Berkeley National Laboratory. Rykoff moved to SLAC in 2012, where he works on galaxy cluster finding and other studies for the Dark Energy Survey and the upcoming Large Synoptic Survey Telescope. He also develops educational astronomy apps for the iPhone and iPad, including CosmoCalc, a full-featured cosmological calculator, and GravLens3, a gravitational lens simulator.

Seating is on a first-come-first-served basis

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