Well we have been offsite this week to attend the Nightfall star party in Borrego Springs. We had hoped for some clear dark desert skies, but as most astronomers know you often have to put up with clouds.
In the last post (November 3, 2018) we showed a photo of the portion of the Milky Way that was visible early in the morning. Now on the next two days we hoped to get in some deep space object observing and some more images of the Milky Way in the evening. The photo below is one view of the Nightfall scope setup area with the mountains in the background and the clear blue morning skies.
|Friday morning and the scopes are being setup at Nightfall in Borrego Springs (Source: Palmia Observatory)|
During the daytime there were free lectures and a whole day of for fee seminars on advanced imaging and image processing techniques. In the photo below, Tom Bash makes a presentation on obtaining high resolution planetary imaging. He presented a lot of useful information. Thanks to Tom and all the other presenters too and to the Riverside Astronomical Society for coordinating the whole event!
|In the seminar room while Tom Bash talks about high resolution planetary imaging (Source: Palmia Observatory)|
One topic of special interest to me was the use of a Powermate lens instead of a Barlow lens. I have been trying to use a Barlow lens in some recent observing sessions and always had a hard time getting the lens system to focus and found I had to insert a couple of spacers in between the scope and the Barlow in order to get proper focusing. Also, the Barlow magnification ratio is not fixed but instead varies depending on the total distance between the scope and the lens. The Powermate lens provides the same equivalent focal length increase and image magnification, but the magnification factor stays the same independently of the distance between scope and lens. That seems to me to be a good feature because whenever I tried to use a Barlow lens, I could never be sure what the actual magnification was and I observed different scale factors on different occasions because of how I set the scope up.
So, I looked up one instance of the Powermate which is made for 2" eyepiece tubes. Wow, it looks pretty impressive but I'm not sure I want to spend over $300 just to try one out. Anybody out there have any experience using this lens and was it worth it!
|Advertisement for Powermate with 2X magnification for 2" eyepieces (Source: TelVue)|
Ok, so the seminars were informative but we also wanted to explore a little bit more of the desert town Borrego Springs. So we met up with OCA and Hams, Marty and Bonnie, and went out for some exploring and lunch and dinner. At least a couple of folks from OCA made it out there. Anyway we had a lot of fun and good to see you and thanks for everything, Marty and Bonnie!
Borrego Springs is well know for all of the metallic sculptures in the area and here is one example where Resident Astronomer George met up with the dragon. There are over a hundred other metallic sculptures in the area by the artist, Ricardo Breceda. Thanks for all of that Ricardo!
|Resident Astronomer George and the Dragon in Borrego Springs (Source: Palmia Observatory)|
Resident Astronomer Peggy had her own encounter with another of the large metallic insect sculptures in Borrego Springs.
Ok, there are hundreds of very impressive metallic sculptures throughout the area but we also hoped to take advantage of the desert dark skies. We all set up our scopes in anticipation but the clouds seemed to come in just as sundown happened. Darn! Well that is the life situation for the astronomer. It turned out for all the nights of our stay in Borrego Springs, I never did see Polaris; it was just to cloudy to the north. In the image below, you can see in the incoming clouds and the glow in the distance is the cloud reflected light from Palm Springs. So even though Borrego Springs is an international dark sky community, when the clouds are out the light from other communities shows up in the night sky. Readers may remember our blog of November 8, 2015, where at our first visit at Nightfall, a mysterious bright light, from as we later learned, a missile launch offshore from California, caused quite a surprise to the nighttime observers there.
|Oh-oh, its sundown but what happened to the clear skies (Source: Palmia Observatory)|
Anyway there were some viewing opportunities through patches in the clouds. Mars was quite bright in the sky and the clouds mostly stayed away from the planet. My plan was to view Mars with just the camera at prime focus on the 560 mm scope and then put on the 2.5x Barlow lens and try to image Mars also. Unfortunately, when I went back to look at the camera images, I couldn't tell which lens setup was used on the one or two captured images of Mars. Oops, I have to be a little more diligent in keeping track of the scope setup.
I analyzed the above image using Photoshop and based on telescope focal length of 560 mm and camera sensor size of 22.3x14.9 mm, and counting the pixels across the diameter of Mars, my estimate was 53 arc seconds. Hmm, that is a bit large compared with the published diameter of 12 arc seconds. Hmm, there was some uncertainty of how to estimate the number of pixels in the image, but still it seems that even if this image was taken with the 2.5x Barlow, the diameter measurement still does not seem to agree. Something is not quite right. Ok, ok, so I have to do better next time. Any ideas about what might be going on here? Maybe I should pick up one of the Powermate lenses that have well defined magnification, even in the hands of amateurs like me!
Anyway the clouds were just too much for many other deep sky objects, so the only object I spied in the sky was the Pleiades. So, as the clouds moved out of the way temporarily, I snapped this image of the Pleiades.
|Spotted the Pleiades (M45) in the lower right corner of this 8 second image (Source: Palmia Observatory)|
So, we just packed up the scope and called it a night. On the second night the clouds seemed to be even thicker so some of us elected not to even set up the scopes. Some folks who stayed up the whole night reported that there were several periods where the clouds dissipated and they were able to get some good viewing. For me, I went out about 10:30PM and found that some portions of the Milky Way were visible, so, rather than set up the scope, I just used my DSLR and tripod to capture a few images. By the way, the red trees in the foreground are not the Red Ocotillo plant that is quite common in the Borrego desert area, but instead is due to all the red lights used by astronomers.
The image below is high overhead view of the Milky Way. I was a bit disappointed in that the Milky Way was not as naked eye visible as it was during our tour in Arizona. I guess the clouds were just reflecting too much light from the larger cities of Palm Springs to the north and from San Diego from the southwest. So even though our nights of observing at Kitt Peak and Mt. Lemon in Arizona was clouded out, the night skies in eastern Arizona were very dark and you could see the bright Milky Way with your own eyeballs.
|Overhead view of Milky Way in this 40 second, 10mm DSLR image (Source: Palmia Observatory)|
Ok, it is time to pack up and leave Borrego Springs. Our next dark sky observing session is planned for Flagstaff, AZ later on in this month. We will be there to tour the Lowell Observatory and attend the AAVSO annual meeting. Remember that in the last post of November 3, 2018, we mentioned that AAVSO help was solicited to monitor light curves from the T Tauri class star, XZ Tau, but because of the clouds I was not able to get a good alignment and had little hope of spotting the star otherwise. So, I can't even pretend to help out in this area and will just have to wait to see what other astronomers have found so far. Anyway, hope to see you all there in Flagstaff!