Affiliation
None
Sun, 09/21/2014 - 10:59

May I, once again, draw the association's attention to the extraordinary behaviour of this star? See, “Web Obs”. I'm in no doubt, at all, about this. I've noticed this phenomenon, intermittently for several years. This morning, I was hoping for an uncontroversial view of M37, but my peace of mind was, once more, shattered! There it was; centre stage, flashing away, as is often the case.

                                             Bill Wilson. (WWJ)

Affiliation
None
Nevermind!

Right after posting that I found your post from last winter where you gave the star names and tycho magnitudes. Now I just have to figure out which stars they are :)

Affiliation
None
Oops again!

  Sorry again but I was bringing up your old chart with no comparison stars. Apparently the AAVSO has added some since then. I find this topic very interesting and I'll try to get out and look at it soon. There are supposed to be clear and cool nights to start the week here, and now I'm on permanent shifts at work with free time before dawn. I'll go to the eyepiece and observe it as objectively as possible, keeping in mind that it's in a crowded field. I'll also try to check the Seeing as best I can. 

Affiliation
None
Further to SAO 58521.

Hi there, Paul ?

 

Thanks for your much needed interest. The four comparison stars you've found, have only been added since yesterday upon my personal request to Tim Crawford who leads The Sequence Team. The 9.9 mag star, I've already been employing as a Tycho 10.0 mag. The other three offerings should now replace, a less satisfactory 10.5 mag, I've been previously using. There are grounds for needing a brighter comp star, but there’s nothing available in the near telescopic field. We must use our own judgement there.

 

I await your conclusions with some anticipation!

 

Bill. billwilson@bluebottle.com

Affiliation
American Association of Variable Star Observers (AAVSO)
Sequence Team Leader

Bill,

I just noticed your statement that I lead the sequence team.  Thanks for the promotion but it is in error and undeserved.

FYI, Mike Simonsen is the leader of the sequence team and I am but one humble member of a number of hard working folks who labor to make, add to and correct sequences.

Otherwise I am not involved in any way with this particular discussion.

Ad Astra,

Tim Crawford, CTX

Sequence Team

 

 

 

 

 

Affiliation
None
Do I understand correctly

Do I understand correctly that this suspected variable is the brightest star in the middle of cluster M-37? The charts I've generated show a lot of "clutter" there (not surprisingly!).

Affiliation
American Association of Variable Star Observers (AAVSO)
SAO 58521

Hi Paul,

Yes, it is the brightest star in M37.  I suggest two things.  First, review the previous thread on this star, especially the multiple nights of time series photometry that showed no variation.  Second, if you do observe it, the best observations would be those that are coincident in time with Bill's observations to confirm or disprove his suggestion of variability.  Off-line email would help to coordinate those activities; or even better, get on the AAVSO chat room:

http://www.aavso.org/chat

and discuss your observations in real-time!

Arne

Affiliation
American Association of Variable Star Observers (AAVSO)
Stars in clusters and visual observations

We have already mentioned in the past that there is no photometric evidence over the years showing variability in this star. The maximum spread between different catalogues is 0.05 mag. around a mean of 9.19 V.

Observers should keep in mind that observing stars inside open clusters is not an easy task, It is prone to a lot of errors due to crowding, different position angles during the observing season, different colors of the stars and so on and so forth.
It is not the same observing isolated stars than stars in crowded fields. The presence of stars too close to the object being observed has a negative effect in the way our eyes/brain perceive the star's brightness.
I always remember cases like ups Sco or V341 Car, stars being close to companions 1.2 mag. brighter than them. As the result of the presence of the companions, I always estimate them fainter than what they really are.
In an open cluster there are all kind of error sources.

But the worst issue is the lack of bright comparison stars.
I wonder how can you get accurate results when the target is one magnitude or more brighter than the comparison stars.

In this case, and no matter how I love and encourage visual observations, no matter what the visual data say about this star, until calibrated and very accurate V photometry showing clear variations is not performed, its "constant" status is not going to be changed.
A K0III+A5V system might show some slow variability from the giant, some variations caused by spots or even long period eclipses, but not the rapid and incoherent variations mentioned. Those are typical of visual scatter induced by some of the error sources mentioned above.

Cheers,
Sebastian

Affiliation
None
  I understand the need for

  I understand the need for disclaimers. If an observer goes to the eyepiece expecting to see something extraordinary, it will probably show up. Percival Lowell saw canals on Mars because that's what he was sure he would see! I just thought observing this star would be worth a try. I'm thinking it's an optical illusion due to the crowded center of the cluster (wow ... M-37 IS a pretty sight in my 10" RFT!) and maybe Seeing conditions might be the culprit. At the same time, I don't think Bill would keep posting about it if he didn't think something is really happening. I'm just trying to help solve the mystery.

Affiliation
American Association of Variable Star Observers (AAVSO)
disclaimers

Hi Paul,

I think your approach is great; helping out where someone is convinced of a variation that no one else is seeing.  The best possible way is to observe simultaneously; if you both see wild variations, that is a far stronger statement than if one observer sees variability and another doesn't, or if one observer sees variability on Monday, but the next doesn't see variability on Tuesday.

The icing on the cake, though, is getting to observe M37.  It is a really pretty cluster!  Monochrome CCD images may be scientifically useful, but they lose a lot compared to any color rendition, or visually watching the changing seeing or the flow of cirrus clouds across a field with a few moments of clarity; things that are highlighted in dense fields.

At the end of the day, though, we want to find an answer, and one that satisfies both Bill and the community.

Arne