Affiliation
American Association of Variable Star Observers (AAVSO)
Wed, 07/19/2023 - 16:09
AAVSO Alert Notice 830 announces a campaign beginning immediately on the YSO V347 Aur. Please see the notice for details and observing instructions.
There are threads for this campaign under the following AAVSO forums:
- Campaigns and Observing Reports: https://www.aavso.org/v-347-aur-campaign-2023
- Young Stellar Objects: https://www.aavso.org/v-347-aur-campaign-2023-01
Please subscribe to these threads if you are participating in the campaign so you can be updated. Join in the discussion or ask questions there!
Many thanks, and Good observing,
Elizabeth O. Waagen, AAVSO HQ
Hello, all! I'm one of the astronomers involved in this campaign. I'll try to keep you all informed about our X-ray observations when they occur, and I'll be trying to make as many optical observations as I can.
In the meantime, please feel free to ask questions about acquiring photometry of the target, or the nature of the object, or anything else you might want to know. I'm an observer, not a theorist like some of my colleagues, but I'll do my best to answer your questions.
Our first XMM-Newton X-ray observations have been scheduled! If all goes according to plan, they will occur
UT 2023-08-20 16:12:45 to 2023-08-21 00:49:25.
Here's a link to the XMM planning webpage for our proposal:
https://xmmweb.esac.esa.int/cgi-bin/obs_search/selectobs_info_cosmos?prpobs=0920480201
So, if you can acquire measurements just before, during, or just after the time period shown above, we will be able to compare directly the X-ray and optical flux from this very interesting object!
Images taken this morning (UT 2023 Aug 06 08:00) show the object has increased in brightness in V-band by over 1 magnitude from its usual quiescent level. It was about V = 14.6. If you can measure it over the next couple of weeks, we would appreciate it very much!
Please feel free to ask questions here in this thread; you can Cc: me directly at mwrsps@rit.edu to be sure I see your message.
Good luck, and thank you!
MWR
Last night, the XMM-Newton satellite acquired images of our target, V347 Aur. The XMM Science center will send us the data in about a week, and we'll be able to start measuring the X-ray brightness of V347 Aur at that time. So far, so good!
In the optical, the star has brightened just as predicted, so the X-ray measurements will occur close to the peak. We could use more optical measurements over the next few weeks so that we can see how quickly the system starts to fade. The field is rising earlier and earlier each morning, so it's not so difficult to observe now. If you're looking for a new challenge in the morning sky, please consider this one.
Thanks to all the observers who have been providing measurements. We appreciate them all!
MWR
The XMM-Newton satellite did detect our target in X-rays! Hoorah! There was a bit of an issue with space weather, but we can deal with that. In the optical, V347 apparently reached its peak brightness just about as predicted, at the same time as in the X-rays.
It's very likely that our second request for time on XMM will be granted, around Oct 1, so that we can have a measurement near quiescence. Please continue to monitor the source until then so that we can verify that (in the optical at least) the star has returned to its low level.
Thanks to all who have been contributing!
The XMM time allocation committee has given us our second (and last) selected timeslot: UT Oct 01 13:18:11 to Oct 01 23:08:11. They were kind enough to add an extra 4400 seconds to our window. Excellent!
A number of AAVSO observers have been contributing measurements to our study. Thank you all very much! Thanks to your efforts, we can see that the system is currently sitting on a plateau after its maximum light. If we can continue to make measurements once every other day or so for through Oct 01 (and a few days beyond), we'll have a very good optical record to compare to the X-ray measurements.
I know it's harder to make good measurements as the system fades, but please continue to do your best over the next three weeks.
Tonight, XMM will make its second and final observation of V347 Aur. Optical measurements tonight and over the next couple of nights will be particularly useful. If you can acquire and B-band images (in addition to V-band), we could use them at this time.
Thanks again to all! The light curve has been very well defined, which will help us to interpret the X-ray observations.
Thanks to everyone who contributed measurements. Our optical light curve shows very nicely the behavior we were expecting to see, and just about on schedule, too. Our XMM observations have been completed, and we're starting to analyze the dataset now. We won't need any more optical measurements, as the star has nearly returned to quiescence, as we had expected.
In a few months, I'll contact those who made major contributions to the light curve for more information, so we can list you properly as co-authors. Everyone who made even a single observation will be thanked in the acknowledgement section.
And I'll thank you now, too!