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Notes from the telescope- May 2012

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SXN's picture
Notes from the telescope- May 2012

Last night and this morning were just gorgeous here in Michigan. A cool, calm, moonless night with good seeing and transparency- it doesn't get much better.

I started the night doing my Chinese fire drill routine, monitoring CVs for outbursts until about 2AM. Then I took time out to visit some old LPV friends in Hercules.

R Her was first up. I really had to dig hard to see it. The 10mm Ethos at 300x did the trick. It is near minimum right now. I called it 15.0. This sequence is actually pretty good, but it could use a comp or two fainter than 14.9. If it had been hazy or the moon had been up, I doubt I would have seen it.

A few other LPVs in Her have issues with the sequences. I can't wait for APASS to finally fill in this region of the sky for the chart team. Hercules has a lot of great stars, but some of these sequences are poor. SS Her was a tough call. I made it out to be 10.0, but I had to exclude the 102 comp from my estimate because it looked too faint to my eye. So I used the 104 and 95, which is a pretty big gap. This one is a pretty interesting customer. It has maxima that seem to vary between either 10.0 or 8.5. It has a relatively short period of 107 days, so you get to see lots of action in a season. I don't think you can over-observe this one.

W Her presented a bit of a challenge too. There is an incovenient gap in this sequence between 124 and 133, so naturally, that is exactly where I needed to make the call last night. I called it 12.7, and that seems to fit the light curve perfectly, but I wasn't near 100% confident at all on that estimate. More like 80%.

Later on I ran into another gap even larger. RV Her has a gap in the sequence between 100 and 112! That is simply too many steps to subdivide in my mind's eye to make an estimate. I prefer 0.2-0.5, but I can deal with up to around 0.7 in a pinch. Anything greater than that and my confidence drops significantly. This is another one of those Miras that has maxima that swing between 9.5 and 10.5. I called it 10.5 this morning, but the light curve is pretty sparse. It's on the rise, but is this max or will it go up to 9.5? 

RT Her was a nice challenge. It was faint, around 14.3. Luckily it sits alone forming a nice elongated triangle with a 140 and a 146 comp. So once you pick it up and can see the 146 you're in business. A couple weeks ago this bugger was down around 15.5, so I was covering it with K35 on AAVSOnet. Its on the rise, so now is a good time to pick it up.

TV Her was faint, and quite a challenge at 14.8. All in all it was a satisfying session. Tonight I plan to do UMa and Dra as well as Lyra LPVs. That ought to keep me busy for hours.

What are you observing?

robinriordan's picture
Observing Strategy

I plan my observing based on a couple of criteria. I select program stars that are within a relatively small region of the sky. Typically, this means one or two adjacent constellations. I use a Meade LXD 75 Schmidt Newtonian with a CCD that has a field of 17 x 21 arcmins. Small slews help me avoid getting lost among the stars. I also restrict myself to either the east or the west on a given night. The meridian flip with my GEM requires that I go out to the telescope and visually acquiring my target. I guess that it is obvious that I operate my telescope remotely from the warmth of my study. Although the mount is perfectly polar aligned, the autostar guide system is simply not up to the task. I do deviate from this procedure when Mike publishes the Inner Sanctum stars for the month. I reserve a couple of nights to capture those denizens of the deep.

I might mention that George Silvis has released version 8 of PhotomCap which reads the newly formatted photometry data pages. You can retrieve this from:

I find this software to be a real time saver for entering data into AIP4Win. As I mentioned in a separate post, I am paying close attention to the V Lyr field. I seem to have lost track of 3UC 240-158111, a star from the UCAC3 catalog which is V=13.69 and B-V=0.00.,Apparent RA: 19h09m41.478s DE:+29?39'49.34". This reminds me of Luke Skywalker losing a planet.

Any and all comments and recommendations are welcomed.

Hope we all enjoy good seeing.

Robin RROA

HQA's picture
lost star

Hi Robin,

I'm not sure you have the right name or position.  3UC 240-158111 is located at

19 09 10.818 +29 38 42.32

with a magnitude of 13.43

No star is located in any catalog at the position that you mention:

19:09:41.478 +29:39:49.34


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