Patrick said: <But seriously, when I first saw your M27 it seemed to not look like <other shots of M27 I've seen. So I goggled "Dumbbell Nebula M27" and <looked at several images. None showed the nebulosity your picture <shows attached to the top and bottom of the nebula. <Is that "extra" nebulosity real or an artifact of the imaging <technique you used? Hi Patrick, The nebulosity is absolutely real, but not captured in most images. I think mine captures the OIII nebulosity really well, but I could go a lot deeper in the Ha band, and I would love to add some SII into the mix. These were all 10 minute sub exposures, but I may try some 20 minute subs on the next clear night, just to see how deep I can go into the Ha wavelengths. Here are a couple of links to other images that managed to get the extended portions of this object. Here is a nice image: http://img98.imageshack.us/i/messier27dummbellnebulaox7.jpg/ Gendler got some of the extended nebulosity, but mostly in the Ha band. He didn't shoot OIII, which is where I got nearly all of my extended data. http://www.robgendlerastropics.com/M27NM.html Ian King got just a hint of the extended nebulosity: http://www.iankingimaging.com/show_image.php?id=170 This one by Tony and Daphne Hallas is simply incredible (as usual), with RGB and Ha data that captures the entire area beautifully: http://www.astrophoto.com/M27.htm This one from the IAC observatory does not have the extended stuff, but is incredible at showing the lobes and ropes in the nebula. This is a narrowband image from a professional observatory: http://www.iac.es/telescopes/IAM/Sep08.html As you pointed out, most of the images on the web fall far short of getting the entire object. They just don't go deep enough. I think my careful calibration and long exposures (10 minutes) allowed me to pull out some of the extended portions that are rarely imaged, which makes me feel pretty good! :) I love this "sport". Cheers, Tyler _____________________________________________ -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Patrick Wiggins Sent: Wednesday, July 01, 2009 9:43 PM To: Utah Astronomy Subject: Re: [Utah-astronomy] Two new narrowband images - Crescent andDumbbell Excellent work, as usual, Tyler. Maybe just once you should post a mediocre image to help some of the rest of us feel better about our images. :) But seriously, when I first say your M27 it seemed to not look like other shots of M27 I've seen. So I goggled "Dumbbell Nebula M27" and looked at several images. None showed the nebulosity your picture shows attached to the top and bottom of the nebula. Is that "extra" nebulosity real or an artifact of the imaging technique you used? BTW, have you seen the work of U-A's newest member/astroimager, David Rankin? Cheers, patrick On 01 Jul 2009, at 16:45 , Tyler Allred wrote:
Hi SLAS.
I finally got my Starlight Xpress camera back from England and got a couple of nights to try it out. I decided to image a couple of old friends. the Dumbbell and the Crescent. I used Optec narrowband filters in Hydrogen Alpha (red) and Oxygen III (green and blue) wavelengths and combined them into color images.
Here is a link to my latest images page. Click the top two images a few times for a full versions of these recent efforts.
http://www.allred-astro.com/gpage8.html
Let me know what you think.
Cheers,
Tyler
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