I Saw a Smudge!

Have been back in AZ for about 10 days, and finally back in Tucson for the next couple months. We had a storm system move through this last weekend, but it finally cleared out. I've been anxious to look for relatively new Comet SWAN (C/2020 F8). There have been spectacular photos from the southern hemisphere, and it has finally moved north enough to get a peak here. Monday was finally clear, so made mental plans to head to Geology Vista, a favorite place of mine to go for good horizons to the east and northeast. The comet is visible just before dawn, and I DO MEAN JUST - was only 4 degrees above the horizon as morning twilight started!

So Monday night I went to bed early (for me, 10pm), intending to get up at 2 to drive the hour up the Mount Lemmon Highway to set up a minimum amount of gear - tripod mounted Polarie - a little tracking mount that will handle my 200mm camera lens... I woke a little early, and got to Geology Vista about 2:30. There was a bright gibbous moon - one reason to head to the mountains, were the lack of haze and inversion layer would make for darker skies, especially near the horizon. Geology Vista is always impressive, as not only are the east and northern skies dark, there is a fine view of the lights of Tucson to the south if you enjoy that sort of thing. I enjoy most views off mountaintops, wherever they are! Anyway, the moon was in conjunction with the planets Jupiter and Saturn, and only about 20 degrees from the moon, even the brightest part of the Milky Way was visible! With the 15mm fish-eye lens, the whole southern sky was captured in this 30 second exposure at right, with an annotated version at right to identify the major players!



To the north, pretty dark skies, even with the bright moon a few days past full. The same exposure taken north shows a much darker sky, and a number of constellations that most people should know. In addition there are a number of radio and TV towers that cover a good part of the Tucson valley seen along a ridge top as well. I've used this spot for observing for decades when something is happening in the northern or eastern skies - from meteor showers to almost daily trips up to document changes in Comet Hale-Bopp way back in 1996! I've even run into friend and co-worker Ed Strittmatter when we both showed up to photograph the comet one morning! Once Melinda and I drove up to watch the Perseid meteor shower one (rare) clear night during a monsoon August - cars were double and triple parked for the crowd that night! Anyway, the naked photo is shown at left and the annotated at right - I even count my shadow as a selfie! The Big and Little Dippers everyone should be able to find - you are welcome!!!




As I mentioned above, Tucson is nestled down in the valley and if you like views of city lights, Geology Vista (GV) is about the 3rd best spot to examine them on the Mount Lemmon Highway. Best is likely Windy Point, just about a quarter mile down the road from GV. Better because the entire sweep of the city is seen from there. It serves as a destination location for bringing up tourists and girlfriends. The morning I was there, I saw three cars come up the hill just below my location at Geology Vista, but they evidently stopped at Windy Point as they came up no further! Second best view would be from Babad Do'ag lookout just past milepost 2 near the base of the mountain. 10 miles less to drive, and still high enough to take in the lights of the city. Geology vista is 3rd best in my opinion.

Regardless, with a small telescope, even a telephoto lens shown here, you can pick out a few details around the city. These were shot with a 200mm lens (about a 4X telephoto). At left is the center of the city (more like the near-eastside ad the entire city can't be seen from GV). The Tucson airport can be seen at upper right, and the keen-eyed who know their way around can likely see Davis-Monthan AFB.  At upper right the bright lights indicate activity in one of the copper mines along Interstate 19 south of Tucson... At right, the east side of Tucson is shown, with the diagonal streak of lights marking Houghton Road, which transverses the entire city from northeast to southeast... In that one you can faintly see the outline of the Santa Rita Mountains at upper left, Mount Hopkins, the cone-shaped center peak is home to the MMT telescope...



Finally, after the above fun stuff - comet time! With sunrise about 5:30, twilight started right about 4am, with the comet only 4 degrees off the horizon! That doesn't leave much of an observing window! I set up a normal lens shooting the area under Pegasus where the comet was to appear, but never saw it in those images. Finally about 10 minutes to 4, I pointed the 200mm where the comet was to be and sure enough, a faint blue smudge was visible in the viewfinder! Re-pointing the camera slightly, I set up to take 40 second long exposures every 40 seconds. I managed 14 of them before the sky was too bright to continue. I then also took some dark exposures (with lens cap on) to measure "hot pixels", and when I got home, took some "sky flats" to be used to correct for lens vignetting (light fall off) in the photo's corners. All were used in making the final image. Shown at right is the stacked 14 frames, about 10 minutes of total exposure. Unfortunately, the comet is moving so fast, even in those 10 minutes, the comet comes out as a streak - if you look at the full-size image. So I repeated the processing, this time stacking the exposures using the comet's apparent nucleus to center on. The result at right is a little better - stars are trailed a bit, but the comet is as sharp as it can be.

Oh and BTW, I could BARELY make out the smudge visually with binoculars, but was far from impressive... Reminds me of the time in 1970 when I woke my parents before dawn to see the BRIGHT comet Bennett - my first one, with obvious coma and a good 5 degree or more tail. My parent's reaction - "Is that all there is"?!

The prognosis for this comet is still up in the air. It might yet be a good photographic comet, given the link to the southern hemisphere photo up top. It never gets very high here, and will always be near the horizon. So we'll see. I'm going to give it a few days and wait for the moon to go away to catch the comet in a darker sky before passing judgement. So stay tuned!