January 2009 - Utah-Astronomy - mailman.xmission.com

Swap meet
by Chuck Hards 25 Jan '09

25 Jan '09

I'm cleaning-out the basement today and have come across all kinds of things that I need to unload. Let's start planning a swap meet for this spring. Not too early; I recall we've done it as early as February, but the better the weather, the better the attendance. I have lots of optics, mirrors, lenses, finderscopes, some filters, the usual ATM stuff. March/April, maybe? FREE STUFF: * Compaq 15" CRT monitor - FREE. * pair of Compaq stereo, amplified computer speakers - FREE * assorted PS2 kid's games - FREE * 5" B&W portable analog TV - FREE * 13" color analog TV/VCR (missing remote but works without it) - FREE * 5" color portable analog TV w/AM-FM receiver & battery pack - FREE Don't make me bury this stuff in the backyard, folks!

1 0

Re: [Utah-astronomy] White dwarfs and YOU
by zaurak＠digis.net 25 Jan '09

25 Jan '09

BTW, Sirius B was the first White Dwarf discovered in 1862, and I think Joe was basically correct in that most Planetary Nebulas do have a White Dwarf and those that do not contain the Degenerate White Dwarfs (the universe does contain degenerates, ha ha). I have only seen the central star in the Ring a few times, as I recall several people saw it with the Grim one night. Sirius B is a challenge, but several SLASer's have the refractors for it, Patrick, Siegfried, and Bob Moore come into mind. I also wonder why my e-mails get bounced, I seem to be able to reply but not able to generate my own posting. Thank You to Rich and Patrick for eventually getting them posted. Erik --- chuck.hards(a)gmail.com wrote: From: Chuck Hards <chuck.hards(a)gmail.com> To: Utah Astronomy <utah-astronomy(a)mailman.xmission.com> Subject: Re: [Utah-astronomy] White dwarfs and YOU Date: Sun, 25 Jan 2009 14:04:27 -0700 Rich, thanks for making sure Erik's posts came through. Funny because I was getting them as recently as a few days ago. I think the key to what Bishop wrote (Observer's Handbook 2009 edition, pg. 309, "Expired Stars") and my recollections, is that Sirius B and Omicron 2 Eridani B are the only white-dwarves *easily seen with a small telescope. *You're not going to see the central star in M57 from your backyard with a 6-inch Newtonian, nor are you going to find the companions of cataclysmic variables with a similar set-up. These two are also very close, as such things go. Om 2 Eri B is only 16.5 light-years distant, Sirius B is what, 8.5? These objects are virtually in our own "back yard". And Om 2 Eri B has the advantage of not rubbing shoulders with the second-brightest star in Earth's sky- it's much more easily seen in the eyepiece. It's a good star-party target that is easily found. "Who wants to see a dead star, one that no longer glows from nuclear fusion?!" I sure would if I were a jr. high kid interested in science. That only leaves the definition of a "small telescope" as grist for the nit-picker's mill. _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://gallery.utahastronomy.com Visit the Wiki: http://www.utahastronomy.com

2 1

Moon & Mars close with Mercury leading the way
by Jim Gibson 24 Jan '09

24 Jan '09

The Moon and Mars are about an arc minute apart and should be visible in the morning if the clouds would kindly go away. Mercury will be close by too. Around 7:45 or so an observer should be able to see all three before the sun comes up.

2 1

White Dwarf hair splitting
by daniel turner 24 Jan '09

24 Jan '09

Like Joe I wondered if the central stars of planetary nebulae were white dwarves so I went to google to get the truth. Turns out to be more complex than I thought. The Crab Nebula is a supernova remnant and so isn't a planetary nebula. The pulsar requires a supernova and the remnant is not a planetary. I found a few sources who mention that the "classical" view is that the central stars of pn's are "precursors" to white dwarves but none mentioned a spectral class for the type. A few pn's are proving to have Wolfe Rayet stars in the center. There are the exposed cores of very heavy stars that are destined to explode as supernovae in the future. The central star of Eta Carina is a star if this type. The argument then becomes that these pn's aren't "genuine" pn's because of the size class of their central stars and their ultimate fate. Sound familiar? DT

3 3

Re: [Utah-astronomy] White dwarfs and YOU
by Jerry Foote 24 Jan '09

24 Jan '09

As it turns out most cataclysmic variable stars have as one of its members a white dwarf. Most of these are visible in small,10" or bigger, telescopes. Jerry Foote ScopeCraft, Inc. 4175 E. Red Cliffs Dr. Kanab, UT 84741 435-899-1255 jfoote(a)scopecraft.com

3 4

(no subject)
by Canopus56 24 Jan '09

24 Jan '09

Daniel schriebt: > Best approach is to use an online service like Heavens Above that will update their orbits in a timely manner. Thanks for the suggests. I was thinking in terms of ploting the orbital path against a Tycho2 field for telescope pointing purposes. The SLAS favorite, TheSky, is nice but overpriced for what it does with respect to freeware alternatives. - Kurt

1 0

Thick as pea soup
by Chuck Hards 24 Jan '09

24 Jan '09

If you live in a fog-enshrouded, low-lying area, it's a good night for laser fun. Even my low-power red pointer shows a visible beam in the fog. You can see density differences in the fog by sweeping the beam of a green laser back-and-forth rapidly. Lower-density patches are darker, and there is structure to them. My daughter waved her laser horizontally, and I waved mine vertically with both fans intersecting in the middle. We got a good 3-D view of the fog density distribution in an enlarging cone with us at the apex. My daughter was surprised to see just how non-homogenous the fog layer really is. Much wispy, filamentary structure, very similar to astronomical nebulae. It reminded me of those computer-generated maps of cosmic structure, also typically a cone-shaped region diverging away from our viewpoint.

2 3

Recommendations for satellite observing program
by Canopus56 24 Jan '09

24 Jan '09

Does anyone have a recommendation for software to track satellites. I have been looking at page http://www.satobs.org/orbsoft.html . Most of the links are dated, but I am favoring Satbuster or Orbitron. - Kurt P.S. - When a launch occurs what is the earliest that you can get a track for it, or is there sometype of pre-launch prediction?

3 2

Re: [Utah-astronomy] Gallery: Wow!
by Jay Eads 23 Jan '09

23 Jan '09

I have a question on the gallery (couldn't be there Tuesday but now my class has moved to Wednesday's so that will make it so I can starting in Feb.). Besides Astro photos can we put sketches in there as well of our observations? On 2009-01-23 03:27, Patrick Wiggins wrote: > Back on line and just checked the gallery and was delighted to see > it's already up to 16 albums. Excellent. > > I'm having fun browsing through the various albums. Joe's shot of > NGC6946 shows just how far along he's come. And Mike's album shows you > don't need a telescope to get some nice astronomically themed shots. > And I got a kick out of the many shots Daniel got of smiling > astronomers (obviously not taken when they were still trying to figure > out why their latest telescope or piece of software is not working). > > Way to go. And thanks again to Ken for making it all possible. > > Clear skies (please!!!) > > patrick > >

4 3

Gallery hint
by Patrick Wiggins 23 Jan '09

23 Jan '09

Just a reminder that while the SLAS Gallery is associated with the SLAS website, the logon and password you use to log on to the SLAS website (http://slas.us/memberlogon.asp) are not the same as those for the gallery. Also, some posters are not modifying the date displayed below each picture. If you do nothing with the date/time option when posting a picture the date shown below each image will be the date you posted the picture, not the date the picture was taken (in case anyone cares <g>). patrick

1 0