Joe, The finest image I have seen of M22 is at this link on Robert Gendler's gallery. http://www.robgendlerastropics.com/M22JM.html This image is a joint effort between Robert and Jim Misti. It was taken with a 32" RC scope and an STL11000 camera. The image is simply amazing. As you can see, there are many yellow stars, but the blue ones are clearly present as well. I sure would like to get some imaging time with that scope! :) Cheers, Tyler _____________________________________________ -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Joe Bauman Sent: Friday, June 12, 2009 11:04 AM To: Utah Astronomy Subject: Re: [Utah-astronomy] Utah-Astronomy Digest, Vol 76, Issue 23 This is very interesting to me. I'm wondering if anyone would like to play with my original images of M22 and see if they can figure out what sort of adjustments they should have, if any. If so, write me a note and I'll put together a package of the relevant exposures. Thanks, Joe --- On Fri, 6/12/09, Don J. Colton <djcolton@piol.com> wrote: From: Don J. Colton <djcolton@piol.com> Subject: Re: [Utah-astronomy] Utah-Astronomy Digest, Vol 76, Issue 23 To: "'Utah Astronomy'" <utah-astronomy@mailman.xmission.com> Date: Friday, June 12, 2009, 10:00 AM See CCD image of M22 at http://www.jburnell.com/STL11000/M22LRGB.jpg You will need to magnify it but many of the stars are reddish. See color image of M80 at http://upload.wikimedia.org/wikipedia/commons/6/6a/A_Swarm_of_Ancient_Stars_ -_GPN-2000-000930.jpg The color magnitude diagram of M 22 http://adsabs.harvard.edu/full/1959AJ.....64...28A shows a lot of stars with a .9 color index which should appear yellow. There are, however, as significant number of stars with a color index of about .1 -.3 which will look blue to white to green. -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Joe Bauman Sent: Thursday, June 11, 2009 10:26 PM To: Utah Astronomy Subject: Re: [Utah-astronomy] Utah-Astronomy Digest, Vol 76, Issue 23 Hi John, No, actually I was referring to my own photo that showed a lot of blue stars at the core of M22. I have been trying to figure why they look blue. It could be that I processed the color erroneously, or maybe the dawn that was breaking made the blue in the sky show up more -- I really don't know. Or maybe M22 just happens to have a lot of blue stars in it. I'm baffled, frankly, and I can't wait to get out when the cluster is higher, and the night is truly dark, and try it again. Best wishes, Joe --- On Thu, 6/11/09, John R. Peterson <docpity@earthlink.net> wrote: From: John R. Peterson <docpity@earthlink.net> Subject: Re: [Utah-astronomy] Utah-Astronomy Digest, Vol 76, Issue 23 To: utah-astronomy@mailman.xmission.com Date: Thursday, June 11, 2009, 5:21 PM
Joe, take a look at this:
http://antwrp.gsfc.nasa.gov/apod/globular_clusters.html
On Thu, Jun 11, 2009 at 10:48 AM, Joe Bauman
<josephmbauman@yahoo.com>wrote:
Joe, were you referencing the APOD globular that had a lot of blue stars (APOD 2004 Oct 14, "Glimpse of a Globular Star Cluster)? That's a false color infrared photo, so blue probably just refers to short wavelength IR. Chuck said it all: The more massive a star, the hotter (i.e., more blue) it burns and so the shorter its life. For this reason, globulars are almost entirely composed of lower mass, older stars, mainly because they don't have much in the way of star-forming dust and gas. And that's because they're outside of the disk of galaxies. It's in the disk, specifically in the spiral arms, where star formation occurs. John R. Peterson
This makes me wonder if one of my basic assumptions is wrong. I thought all globulars were extremely ancient. But could a population of blue stars be as old as red ones? Can someone help me understand this? Thanks, Joe
------------------------------
Message: 3 Date: Thu, 11 Jun 2009 12:38:23 -0600 From: Chuck Hards <chuck.hards@gmail.com> To: Utah Astronomy <utah-astronomy@mailman.xmission.com> Subject: Re: [Utah-astronomy] My new solar mount setup Message-ID: <2541d8030906111138n611656bv93a0e21b91f5f67b@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1
Kurt , does your own PST display ghost images near the edge of the FOV? Did you buy yours new, or used?
_______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php Visit the Wiki: http://www.utahastronomy.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php Visit the Wiki: http://www.utahastronomy.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php Visit the Wiki: http://www.utahastronomy.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php Visit the Wiki: http://www.utahastronomy.com