Proposal #304

I would like to participate in Arne's V838 Mon observing project but the star is obscured by trees from my site. Arne's proposal was posted on the AAVSO forum yesterday (Dec. 16).

Excerpts from Arne's proposal:

"V838 Mon is a very peculiar star, having an outburst to 6th magnitude in 2002, a decline to 16th, and now over the past decade, a rise to about 13th magnitude.

... the star continues to increase in brightness; the source is still extremely red; and there seems to be a long-period variation in brightness of about 300 days. Is this real, or is it a seasonal artifact? Are there short-term variations that have been missed by the daily monitoring?

I would like people to monitor this star, but with specific requirements. If you meet those requirements, I will comment on your results on this thread. Hopefully, we'll both learn something from the experience! I intend to monitor V838 Mon myself using a remote telescope, so you will see my results as well (and you can comment on them too!).

All observations must be in at least two of the common Johnson/Cousins filters. B&V would be great, though the star is quite faint at B; V&I are also good, as examples.
You need to observe with at least 3 sets of measures per visit. If you use B and V, for example, you should observe in the pattern BVBVBV. The submitted estimate per filter should be the mean and standard deviation of these sets.

You need to observe with at least 3 sets of measures per visit. If you use B and V, for example, you should observe in the pattern BVBVBV. The submitted estimate per filter should be the mean and standard deviation of these sets - don't use the error that you get from your usual analysis software.

As an extra, there is a variable star that is currently listed as a comp star in the field. Sebastian looked at this star's light curve in GAIA, and says that it is an SPB variable with 0.03mag amplitude, with no period given. Let's monitor it as well and report data on both stars."

I would like to observe this star in B, V, and Ic with a once daily cadence. Observations should started ASAP and continue until this star is no longer observable, May 2023.

I discussed my proposal with Arne by email today, Although someone is already observing this star with an AAVSOnet telescope, he thought is would be useful to have another observer using a different AAVSOnet system for this project. Images should go to my VPhot account, SPP.

Phil Sullivan SPP