Mat, I read Jay's blog about the mud adventure. What was old, is new again, lol. One day I'll tell my decades-old tales of driving through foot-deep snow to dark-sky sites, in my '74 Toyota Landcruiser with 34" tires and 10" lift kit. LOL! (I miss than money-pit of a vehicle, sob!) As far as the horsehead incident goes, a couple of things could be taking place. Were the views with the different filters in the same telescope? Think about the way narrowband filters work. It's the interference principle. They are very sensitive to f-ratio. Think angle of incidence and the tiny distance between reflective layers of the coating. Interference filters can have a very different effect between telescopes of differring f-ratios. One reason H-a solar filters work best with long f-ratio objectives. If it was the same telescope, then I suspect one filter was more effective at reducing the ambient LP at your observing site. They both probably passed the same wavelengths, within a few percent, but one might have blocked the predominant LP wavelengths better than the other. On Tue, Feb 21, 2012 at 4:08 PM, Hutchings, Mat (H USA) < mat.hutchings@siemens.com> wrote:

As far as the horsehead goes, I did hit it with an O3 filter (Orion brand) and this was verified by Jorge. A very curious thing happened though, that I cannot explain. Jay has an H-Beta filter (Orion brand) that he let me use on the same eyepiece (my T.V. 22mm Panoptic) that Jorge and I observed the horsehead with and it actually looked much more apparent with the O3. This is not supposed to be how it works. The H-Beta is supposed to make the horsehead more visible. Anybody have any thoughts on this?

Nice report, Mat! I can't wait for warmer, drier weather. Thanks, Joe ________________________________ From: "Hutchings, Mat (H USA)" <mat.hutchings@siemens.com> To: Utah Astronomy <utah-astronomy@mailman.xmission.com> Sent: Tuesday, February 21, 2012 4:08 PM Subject: [Utah-astronomy] observing report for 2/17/12 Amazingly enough, the sky cleared last Friday, so my daughter Sarah and I headed out to a site near Vernon for a deep sky session with Jay, Jorge and Josh. We were driving along and I got a message from Jay who was about 30 minutes ahead of us saying that he was on the dirt road just past Vernon and all was looking good. Just when Sarah and I were about a mile past the Pit-N-Pole, I got another call from Jay and he said DON'T come this way as he was in 4-wheel drive and nearly got stuck in the mud on the final road to the site. The ole minivan would not fare so well in those conditions, so we turned around and headed back to Pit-N-Pole. Jay was able to back out without getting stuck and then he started heading back to the Pit. So it turns out that this new site is not so good after it has been snowing. And since this has been a pretty snow-free year, it may not be a good winter site at all. We'll keep looking. Okay, so after making quick calls to Jorge and Josh to tell them of the venue change, we got down to setting up and getting ready for the night. Just about as Sarah and I were finished setting up, a somewhat muddy Jay (his vehicle that is) arrived. Jorge arrived shortly thereafter. After dark fell, I got started on my observing list. I had a couple of galaxies in Fornax, and Eridinus to hit as well as some planetary nebulae. The bulk of my hit list was open clusters throughout Puppis, Orion, Gemini, and even heading into Pyxis. I was also determined to hit the horsehead. Sky conditions were okay. Seeing was not the greatest, as there was a fair amount of twinkle going on, and transparency was not the best. Apart from a couple of DOH moments like searching for an open cluster while still having my O3 filter in place, the night progressed well and I hit most of the items on my list. The items that made my "very cool" list were N2194, N2158, N2237, N2477, N2438 and M81 and M82 (those 2 galaxies are always very cool to me). As far as the horsehead goes, I did hit it with an O3 filter (Orion brand) and this was verified by Jorge. A very curious thing happened though, that I cannot explain. Jay has an H-Beta filter (Orion brand) that he let me use on the same eyepiece (my T.V. 22mm Panoptic) that Jorge and I observed the horsehead with and it actually looked much more apparent with the O3. This is not supposed to be how it works. The H-Beta is supposed to make the horsehead more visible. Anybody have any thoughts on this? Jorge had the same impression, better with the O3. Anyway I actually hit the horsehead and I'm happy about that. Conditions got frosty (this was at the Pit after all), so I got my 12V hairdryer going on my eyepiece, Rigel Quickfinder and optical finder. Just the same as the last time I had to use it, one application gave me about 30 minutes reprieve from the frost. Then I have to use the drier again. Jay on the other hand was happy as a clam with his new dew zapper system. He was not inhibited by the frost at all. Around midnight or so, we all packed it up and headed our separate ways. All in all a good night for February observing. ---------------------------------------------------------------------------- This message and any included attachments are from Siemens Healthcare and are intended only for the addressee(s). The information contained herein may include trade secrets or privileged or otherwise confidential information. Unauthorized review, forwarding, printing, copying, distributing, or using such information is strictly prohibited and may be unlawful. If you received this message in error, or have reason to believe you are not authorized to receive it, please promptly delete this message and notify the sender by e-mail with a copy to Central.SecurityOffice.Healthcare@siemens.com Thank you _______________________________________________ Utah-Astronomy mailing list http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Send messages to the list to Utah-Astronomy@mailman.xmission.com The Utah-Astronomy mailing list is not affiliated with any astronomy club. To unsubscribe go to: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Then enter your email address in the space provided and click on "Unsubscribe or edit options".