The Almost Perfect Night

Sometimes things just work out. All the stars align, and your day, or night, turns out better than you'd ever hoped. I hope it has something to do with paying it forward, like giving the Boy Scouts a few bucks without even taking the popcorn they were selling the other day. "Here, I can't eat the popcorn, but here's a few dollars for a good cause." Whatever the reason, when you have one of those days it feels good, and you can't wait for tomorrow, to see if it can be as special as today.

Saturday night into Sunday morning was one of those special times for me. It was the third night in a row with clear skies in the forecast. I'd had a couple good nights at the telescope logging 150 variable star observations or so, but the moon was waxing towards full, and the sky was getting less and less friendly in the evening. So I decided to get some sleep after dinner and wake up after midnight to go out and observe as the moon was setting, hoping to take advantage of the last 90 minutes before morning twilight when the moon was actually down for the night. 'Dark time', as astronomers call it, is precious.

I fell asleep hard and got some great shut-eye. I woke up around midnight, made a pot of coffee and headed for the dome. The sky was clear, no haze, no high clouds, and very steady seeing. The stars barely twinkled as I looked up. The moon was still pretty high and casting its glare across the heavens, so I decided to start the night observing in the north in Cassiopeia. Turning away from the moon, the dome protected me from the light shining in through the dome slot, and Cassiopeia (Cas) was riding high in the northeast at this point. I observed all the long period variables in my program in Cas, and then did all the cataclysmic variables (CVs) in Cas before taking a break.

T Cas is one of the blood red stars in the sky. It was really too bright to observe in the telescope, so I made my estimate with the 50mm finder scope. S Cas gets really faint at minimum, and I seem to always miss her. I was able to catch her rising from the depths at 14.0V.

The best part of the whole thing was the telescope was pointing extremely accurately again after a long time being offline and under repair. I'd had to take Janet (the Classic 12" LX200) out of the dome, dis-assemble her and ship off the electronic components to be rebuilt. I've made over 50,000 variable star estimates with Janet over the years, and I missed her dearly while she was down. I have a newer 12" GPS LX200, but I really prefer observing visually with the Classic for a number of technical reasons I won't bore you with here. I was a little reluctant to take her apart and ship off her guts, and then put her back together again. But I had no other options, so I had to grow a little and trust myself with her fate.

I am very pleased to say, Janet was working perfectly. Accurately slewing to objects on command, without hesitation, enabling me to do an observation every 90 seconds to 2 minutes. Man, I missed her. I forgot how much fun this can be when everything is working right!

I moved on to cataclysmic variables in Perseus after a short java break. The moon was still pretty high, but since I was pointing nearly straight overhead, I was still able to log faint observations of magnitude 14.8V. On a clear, moonless night I can usually reach as faint as 15.5 visually, so the moon was definitely impacting the sky, but I was comfortable viewing overhead and out of the glare of the moon, protected by the dome. The weather was about as perfect as you can hope for. No wind, no dew, no frost, no fog and mild temperatures around 45F.

This time of year, Orion and Taurus are nearly due south at 5:30AM, and it was my intention to observe all my program stars in Ori and Tau about this time until dawn. But Orion beckoned me as it rose higher in the SE, so I rushed it a little. It was only 3:45 so I was ahead of schedule. ORI is one of the few constellations I observe several variables south of the celestial equator. I prefer to remain seated while observing, and I call chasing after variables or other objects down in the haze of the horizon "dumpster diving". There are plenty of things to observe in the clarity of the zenith, it seems a waste of time to go looking for trouble and fields where the best I can do on a good night is 14.0V.

Nevertheless, I headed to Ori because I knew the prospects of detecting an outburst of a CV were good here. CZ Ori, CN Ori and V1159 Ori are pretty active stars. Several times, I have caught the "Orion Trifecta" all in outburst on the some night. I wasn't disappointed. CN Ori and V1159 Ori were in outburst. I swung up to Auriga to do the few CVs there, hoping maybe for SS Aur to be active, but nothing to see.

The moon was still well above the horizon, so I went back to Perseus overhead and logged observations of all my program Miras in PER. About 4:45 I moved on to Miras in TAU. The sky was noticeably darker, and the shadows outside were growing long towards the east. I only have a dozen or so variables I observe in Tau, but several favorites.

W Tau is right in the midst of the Hyades cluster, so the field is a magical star showplace. Z Tau is an extremely interesting star, exhibiting a period change over the history of AAVSO observations, and it is one of the most challenging close double stars that are variable to observe in the whole sky. I think the separation is about 1.5 arcseconds.

But S Tau has been an enigma to me for a decade. Its period is almost exactly 365 days, and its maximum light has coincided with the time it is in conjunction with the Sun since I can remember. I don't think I have ever made a positive observation of it in all my years as an observer! I always log <14.8 or something, which means it is fainter than 14.8, but I can't see it. On the morning of October 12, 2008 I made my first positive observation at 13.6V! I was shocked and thrilled, and double checked it, like 12 times, to be sure!

Kind of like birders, who have life lists of birds they've seen or not, I checked off S Tau this night.

5AM and the moon was essentially down. Now I was going to take advantage of the darkness to chase after possible eruptions of CVs in Gem, CMi, and Cnc before calling it a night. Canis Minor and Gemini were quiet this night but when I got to Cancer I was rewarded with catching three outbursts before dawn ended the fun.

The first was AK Cnc. I have a special affinity for this star because of my involvement with deriving the sequence of comparison stars used to estimate it. When I started observing this star in the 1990's, the accepted sequence of comp stars used for estimating its brightness was screwed up. There were three stars labeled 131, 132 and 134 that played havoc with my brain the few times I ever saw it this bright. When we finally got excellent photometry for these stars and revised the charts, the reason became clear. They were all 13.2V! The new sequence is one of hundreds I am responsible for improving since 2003, when I was put in charge of the volunteer team making new sequences for the AAVSO and other international variable star organizations. Its been a while since she went into outburst, and I was pretty sure I was the only one in the world to witness this event, since it is such an early morning target and most of Europe was clouded out.

That is one of the coolest things about observing variable stars, especially CVs. You may very well be the only person on Earth who knows a star has gone into outburst, or reached maximum or minimum, because there just aren't that many people observing these objects. Professionals don't have time to monitor thousands of variables, so the majority of this work is done by devoted (read obsessed) amateurs!

The second reward was GZ Cnc. This is an enigmatic CV that defies classification up to now. Its fairly active, but it resides in one of those blank patches of sky, devoid of bright stars, and finding it is almost as hard as detecting it in outburst.

The last surprise before calling it a night was to find AT Cnc in outburst. AT Cnc is a Z Cam type star. These stars are known for getting stuck in 'standstills' on the way down to minimum from outburst. AT Cnc had been known to stick in standstill for months at a time around 13th magnitude, defying anyone to catch it at minimum or in outburst. In fact, most of the observations I have logged of this star are in standstill at 13th mag. I've only witnessed a couple outbursts, and I don't think I've ever seen it at minimum. Tonight, it was uncommonly bright at 12.8V.

It was still well before dawn when I parked the telescope and closed the dome, but I was spent physically. Straining against the moon and trying to see as faint as you can see with each observation of a quiescent CV is surprisingly physically taxing. But I was happy as hell.

The weather, the telescope and the stars had all combined to give me one of the most rewarding nights at the eyepiece in a long time. If it had been new moon it would have ranked among the best nights ever.

I'll take a near miss of perfection. Most of life is perfection minus a couple percent. That's good enough for me.

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