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Notes from the telescope- April 2012

SXN's picture
Joined: 2010-03-12

Last night (this morning actually) I spent some time with my favorite Miras in Draco. T Dra, the variable double was a delight to observe as always. The sequence when it is in this range of brightness is so convenient it makes it easy to do, so you can spend a few extra moments afterwards enjoying the redness of this particular beast.

One of my all time favorite "twofers" (two variables in one FOV) is W and X Dra. I usually synch my LX200 on the Cat's Eye Nebula (NGC 6543- how easy is THAT to remember!), enjoy a quick look at the Cat's Eye and then slew to W and X Draconis. Last time is the first time I ever recorded them as being the same brightness. They both have pretty extreme ranges (X= 8.9-15.8V and W= 8.9-15.4V), so this has got to be rare. Careful not to use the combined magnitude of the 109 comp near X Dra when doing W at this magnitude. I tried doing it with my 80mm finder and realized I was creating trouble for myself. Look for yourself, and see what I mean.

I also clocked V Dra in at less than 15.0. I could see the 144 and 150 just fine, but no hint of V Dra. Just goes to show you, even Miras can have some surprises. The range in VSX is stated as being 9.5-14.7V, but that is just an average. Obviously, V Dra doesn't care what we have in the catalog. it is hiding out deep in the inner sanctum this week.

That's all for now. What are you looking at?

Looking at
Gustav Holmberg
Gustav Holmberg's picture
Joined: 2011-10-29

SXN wrote:

That's all for now. What are you looking at?

I have enjoyed following T Cephei through its maximum these last months. The star is good placed for us at higher latitudes - I live in Sweden -, easy to find and has become one of my favorites when observing with binoculars. Also, using binoculars, my spring season has included classic Miras such as U Orionis, chi Cygni and R Leonis, as well as some semiregulars I like (TX Dra, Z UMa, RY UMa, V CVn, AF Cyg, CH Cyg).

CCD-wise, I observe with telescope time bought on commercial remote telescopes operated by iTelescope and Sierra Stars.  For example, I've been observing some of the stars on a programme of 50 underobserved Miras run in collaboration with a number of fellow Swedish variabilists. The list of programme stars was chosen by Hans Bengtsson (BHS) on the criteria that they have no or very few observations in the AID, be fairly bright at maximum, and be distributed throughout the sky, so that some is available for observation at any time. We've had very good help from the AAVSO sequence team in getting sequences for these stars set up!

We have been observing since February. Who knows what we will find?

Already, it is apparent that some of these Miras are out of synch with predictions which is not surprising, since elements in the catalogues in some cases are decades old; some stars don't even have elements. 

For example, we've followed v483 Aurigae as it approaches a max; the programme's first maximum observed, so far, was for ER Lyr which peaked around 10.5 circa 1 April, about a month off from predictions using the elements in GCVS.

/Gustav, HGUA

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