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PeterSurma
member
Reged: 08/24/06
Posts: 85
Loc: Heidelberg, Germany
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Last night, I finally succeeded in observing a single Star in M31. It's not easy doing this because of Andromeda's distance modulus of m-M = 24.5. Even in a 20" scope (17mag limit) you need a star of M=-7.5mag in the visual band. Those stars are very rare and extreme in their physical properties. So finally I managed to see AE And in M31 in
my 20" at good seeing conditions and under a 21.3mag/sas sky. AE And lies pretty close to M110 at (2000.0) 00h43m02s / 41°49'12".
Try it out ! - it's currently 'pretty bright' (well, sort of :-), rougly 16.5mag I'd estimate. Good luck hunting.
Peter
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Web: http://www.eyes4skies.de/home_EnglishVersion.htm
Edited by PeterSurma (08/28/08 07:46 AM)
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sgottlieb
sage
Reged: 07/22/07
Posts: 243
Loc: SF Bay area
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Congratulations on nabbing this star! I'm curious if you also tried the luminous blue variable AF And at 00 43 34 +41 12 09?
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Steve Gottlieb
18" f/4.3 Starmaster
Adventures In Deep Space - New article on MASH planetaries
7500+ NGC/IC Visual Descriptions
NGC/IC Project
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PeterSurma
member
Reged: 08/24/06
Posts: 85
Loc: Heidelberg, Germany
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Hi Steve,
I tried yes, but could not get it. I guess AF is more difficult anyway because of the M31 background light below it. I also tried similar guys in M33, but no luck either (yet :-).
It seems I've been lucky enough to grab AE in an outburst phase (and seeing was pretty good).
I hope to have another chance for those LBVs on the week-end (hopefully under truly excellent skies on 2500m altitude). Because of their irregular variability it's surely worth re-trying all of them now and then...
Have you observed one of those already ? (I haven't checked your site on this yet)
Peter
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Web: http://www.eyes4skies.de/home_EnglishVersion.htm
Edited by PeterSurma (08/29/08 05:50 AM)
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PeterSurma
member
Reged: 08/24/06
Posts: 85
Loc: Heidelberg, Germany
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If someone else is keen on observing AE And, checkout my website for a premature obs report here:
http://eyes4skies.de/Internet/Astro/BeobachtungsReports/BeobachtungsReports_files/BeobReport_2008_08_27_KABR.htm
This is all in german, I'm sorry, but at least grab the chart + DSS if you like...
Peter
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Web: http://www.eyes4skies.de/home_EnglishVersion.htm
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MessierScott
super member
Reged: 06/18/07
Posts: 188
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Quote:
Congratulations on nabbing this star! I'm curious if you also tried the luminous blue variable AF And at 00 43 34 +41 12 09?
Steve (or anyone else), do you have more precise coodrinates for AF And? The Digitized Sky Survey image with these exact coordinates and 1 arc-minute by 1 arc-minute shows 2 stars.... 1 to the SE of center and another just west of center.
I'm heading down to our dark sky site in about 3 hours for the weekend and right now the sky is an incredible deep blue.... maybe good seeing tonight? I hope so! I'm mainly going to be focusing on Local Group galaxies, Minkowski's, and Abell planetaries, but this sounds interesting as well!
Thanks!
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Scott Kranz
20-inch f/4.3 Starmaster w/Zambuto mirror, Feathertouch focuser, GO TO & tracking
7-inch Starmaster
H-alpha Coronado PST
Denkmeier II binoviewers w/24mm Panoptics
16x80 binos
Astronomical Society of Kansas City
Astronomical League Messier, Meteor, Sunspotter, & Asteroid Observing Programs Coordinator
ASKC Dark Sky Site
Edited by MessierScott (08/29/08 02:43 PM)
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Bill Weir
scholastic sledgehammer
Reged: 06/01/04
Posts: 893
Loc: Metchosin (Victoria), Canada
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I'll be with some big glass this weekend, so it's now on my list.
Bill
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6'' Orion SkyQuest
12.5'' f/5 Custom Truss Dob
William Optics 80mm ZenithStar II ED Doublet
f/5 25" newtonian on a giant GEM, any time I want
Observing sessions grand total for 2007, 171.
So far in 2008, 115
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sgottlieb
sage
Reged: 07/22/07
Posts: 243
Loc: SF Bay area
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Quote:
Steve (or anyone else), do you have more precise coodrinates for AF And? The Digitized Sky Survey image with these exact coordinates and 1 arc-minute by 1 arc-minute shows 2 stars.... 1 to the SE of center and another just west of center.
I'm heading down to our dark sky site in about 3 hours for the weekend and right now the sky is an incredible deep blue.... maybe good seeing tonight? I hope so! I'm mainly going to be focusing on Local Group galaxies, Minkowski's, and Abell planetaries, but this sounds interesting as well!
Thanks!
This may be too late to reach you for this weekend, but based on Aladin, the precise position for AF And is 00 43 33.1 +41 12 10. The main problem is that this star is not too far southeast of the center of M31 just along the eastern edge of the central hub and it's superimposed on a relatively bright background. A good reference is the globular cluster G233 which is located 4' south of the LBV. The globular would have to be easily visible to have a shot at the M31 variable.
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Steve Gottlieb
18" f/4.3 Starmaster
Adventures In Deep Space - New article on MASH planetaries
7500+ NGC/IC Visual Descriptions
NGC/IC Project
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MessierScott
super member
Reged: 06/18/07
Posts: 188
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Thanks Steve!
I'm at our dark sky site right now (Isn't todays technology great!!!!). Last night my SQM registered a 21.62 during several checks around 3am. Had no problem seeing AE And. Just a faint star....but to think about what it really is....... Very Kewl!!!!!!
Also had a easy time picking up the globulars G1 and G2. G1 was OBVIOUSLY not a stellar point, but a fuzzy ball next to the 2 companions stars that form the tight little triangle.
Was up till 5 this morning. We have about 50 club members out here for the weekend. Buying these 40 acres and putting in electricity was the best thing our club has ever done!!!!!!
Looks like we might have another great night ahead! Time for some lunch and an afternoon nap!
Thanks again!
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Scott Kranz
20-inch f/4.3 Starmaster w/Zambuto mirror, Feathertouch focuser, GO TO & tracking
7-inch Starmaster
H-alpha Coronado PST
Denkmeier II binoviewers w/24mm Panoptics
16x80 binos
Astronomical Society of Kansas City
Astronomical League Messier, Meteor, Sunspotter, & Asteroid Observing Programs Coordinator
ASKC Dark Sky Site
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Bill Weir
scholastic sledgehammer
Reged: 06/01/04
Posts: 893
Loc: Metchosin (Victoria), Canada
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Quote:
Try it out ! - it's currently 'pretty bright' (well, sort of :-), rougly 16.5mag I'd estimate. Good luck hunting.
Peter
I'm guessing it must be brighter than 16.5 because on Friday evening I was able to hold it about 25% of the time at around 450X with averted vision using my 12.5" dob. With my friend's f/6 20" dob at whatver a 6mm Radian give we were able to hold it staed almost 100% of the time.
Last evening I wash having dinne with a couple of project leaders on the Hubble ACS Virgo Cluster Project. They were quite intrigued to hear that something like this was possible. Patrick Cote (one of the members) said it must be a blue giant. I had missed the part where you stated it is luminous variable. Next time I see him I'll have to pass this on.
Is there a site where I could find the evidence that shows this actually is a star in M31?
Bill
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6'' Orion SkyQuest
12.5'' f/5 Custom Truss Dob
William Optics 80mm ZenithStar II ED Doublet
f/5 25" newtonian on a giant GEM, any time I want
Observing sessions grand total for 2007, 171.
So far in 2008, 115
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PeterSurma
member
Reged: 08/24/06
Posts: 85
Loc: Heidelberg, Germany
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Bill,
you might have a look at
http://en.wikipedia.org/wiki/List_of_most_luminous_stars
(but note that bolometric magnitudes are - by far - not visual ones for there stars, the correction to V-mags is large, due to the large UV-output of these stars !)
AF and AE And are definitely members of M31.
Evidence can be found in a paper by Szeifert Th. et al, 1996 A&A 314..131S. I am currently writing up a little article on those objects. I'll make sure to post a link, when done.
Peter
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Web: http://www.eyes4skies.de/home_EnglishVersion.htm
Edited by PeterSurma (08/31/08 06:14 PM)
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Bill Weir
scholastic sledgehammer
Reged: 06/01/04
Posts: 893
Loc: Metchosin (Victoria), Canada
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Wil the article be in english? When we were talking about this sighting at the star party were were at, the first thing out of everyones mouths was, "how do you know it's in M31?" Then I was asked to give a few mintue talk a out next club meeting about the search.
Interestingly enough, on the Friday night at the other end of the field an imager was shooting the galaxy using an 8" reflector and an ST11000. Saturday, after he finished processing the image, we had a look at it, and with enlarging the area you could easily pinpoint the star. Too bad he didn't use a coma corrector because the star was anything but a pinpoint.
Bill
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6'' Orion SkyQuest
12.5'' f/5 Custom Truss Dob
William Optics 80mm ZenithStar II ED Doublet
f/5 25" newtonian on a giant GEM, any time I want
Observing sessions grand total for 2007, 171.
So far in 2008, 115
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sgottlieb
sage
Reged: 07/22/07
Posts: 243
Loc: SF Bay area
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Quote:
When we were talking about this sighting at the star party were were at, the first thing out of everyones mouths was, "how do you know it's in M31?" Then I was asked to give a few mintue talk a out next club meeting about the search.
I believe there are only 4 of these superluminous blue variables known in M31 and a handful in the Milky Way, so they are well studied due to their unusual spectrum. The first one (AF And) was discovered by Hubble and Sandage back in 1953 (see http://tinyurl.com/5ljzo7 for the paper) along with a few similar stars in M33. Eta Carina and S Doradus (maybe P Cygni) are in the same class, but the relatively faint magnitude of AE and AF Andromedae pin down the membership in M31.
--------------------
Steve Gottlieb
18" f/4.3 Starmaster
Adventures In Deep Space - New article on MASH planetaries
7500+ NGC/IC Visual Descriptions
NGC/IC Project
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lymorkiew45
sage
Reged: 12/30/07
Posts: 323
Loc: Anaheim
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Is there a finder chart for this star? I looked it up on the internet and came up with nothing. Will it be visible in a 12" scope? Is it easy to find? I think I need to test my skills on some of the globular clusters of M31, but these objects are faint, and difficult to find, and I need a good chart to find them, but AE And sounds like a formidable target for my scope, with my 20 years experience in the hobby...clear skies... 
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Control Yourself, let others do as they will, this does not mean you are weak, control your heart, obey the principles of life, this does not mean others are stronger. *Lung Ying Mor Kiew motto*
Starfinder 16 EQ, and dob
DS-10
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Z12
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Orion ultrablock filter
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Bill Weir
scholastic sledgehammer
Reged: 06/01/04
Posts: 893
Loc: Metchosin (Victoria), Canada
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Quote:
Is there a finder chart for this star? I looked it up on the internet and came up with nothing. Will it be visible in a 12" scope? Is it easy to find? I think I need to test my skills on some of the globular clusters of M31, but these objects are faint, and difficult to find, and I need a good chart to find them, but AE And sounds like a formidable target for my scope, with my 20 years experience in the hobby...clear skies...
Peter's link (above) to his report (in German) has a perfect pair of charts for finding this star. The little asterism of 4 stars wasn't difficult to find at all. From there, using my 12.5" it got much more difficult. It was very comparable to seeing the central star in M57 only a little more difficult. I think it's very "seeing" dependent. Then it also took high power. Note how I stated above it was at 450X and I was hand tracking. Your site will also have to be reasonably dark.
G1 is a piece of cake with a 12". Heck, I've been able to make it out with my 6" dob.
Good luck.
Bill
--------------------
6'' Orion SkyQuest
12.5'' f/5 Custom Truss Dob
William Optics 80mm ZenithStar II ED Doublet
f/5 25" newtonian on a giant GEM, any time I want
Observing sessions grand total for 2007, 171.
So far in 2008, 115
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PeterSurma
member
Reged: 08/24/06
Posts: 85
Loc: Heidelberg, Germany
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Well, I should add that these LBVs are investigated by spectroscopy a lot of course (see e.g. the paper I mentioned). They are very interesting to professionals working on stellar physics. The red(blue)shift of spectral lines of AF and AE And fit into M31 velocity-wise, and the spectra show that it must be a very luminous star (of 30000K), so as Steve was saying above, its faint magnitude also implies that it must be far away. Its memebrship with M31 is solidly proven, I think.
Peter
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Web: http://www.eyes4skies.de/home_EnglishVersion.htm
Edited by PeterSurma (09/02/08 03:04 PM)
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