Affiliation
American Association of Variable Star Observers (AAVSO)
Sun, 06/21/2015 - 19:57
Hi All
VSNET emails reporting observations indicating a rapid brightening of AG Peg to around 7.2V.
I have obtained a V band image taken June 21.8109 UT (JD 195.3109) showing the star at V=7.24 (0.01) using the 82, 100 and 107 comparisons in our AAVSO sequence.
Good Observing to All
Steve
Hi Steve,
Yup, she's up alright and far brighter last evening than at any time that I've seen the star in the course of my 50 years of observing it. In fact, AG Peg probaby hasn't been this bright since the 1930's!
I likewise note that the range of the current eruption is (at least so far) just about one half that of the original 19th century outburst. Unfortunately, it looks as if the latest brightening of the outburst may already be peaking and that most of the recent rise went unobserved by AAVSO contributors. Did any of our sky survey cameras happen to have imaged the field of AG over the past two months perhaps?
J.Bortle (BRJ)
Don't forget to check the BAAVSS database folks. There is a fairly complete record throughout the winter and spring months. The largest gap between April 28 and May 27 reveals only a 0.1 mag change.
Most BAA observers upload their data at the end of the month (for some reason), so we will have to wait for Junes data - but John Toone did report AG Peg brightening from 8.7 on June 7 to 7.4 by June 21 (I also had 7.4 on the morning of June 22), so it looks as though nothing has been missed and the outburst continues. John Toones data has yet to appear in the database, so you won't yet see it on any plotted light curve.
The BAAVSS database can be seen at http://britastro.org/vssdb/index.php and choose "review data for a star". You then get the opportunity to see the data or light curve. Click and drag on the light curve for a zoom in feature!
Gary
Hi John,
The only AAVSOnet telescope that is monitoring AG Peg is BSM_HQ. It took BVI datasets on 4/12, 4/16, 4/18, 5/7, 5/14, 5/15, 5/18, 5/21, 5/23, 5/24, 6/07, 6/14 for the current season. None of that data has been analyzed and submitted to the AID yet. If I get a chance this week, I'll see if I can get that data submitted.
Arne
Gary has a good point to check the BAA archives. Another good reference would be the VSOLJ database.
I've uploaded the BSM HQ BV photometry from this season.
Arne
Thanks very much for uploading the most recent AAVSOnet BSM photometry on AG Peg to the AAVSO International Database, Arne! The B and V data from January, April, May, and June definitely improve the picture of the system's behavior leading up to the outburst itself.
Clear skies,
Elizabeth
AAVSO Alert Notice 521 discusses the historic outburst of AG Peg underway, its first since 1860-1870! Don't miss observing this extremely rare event.
Good observing,
Elizabeth Waagen, AAVSO HQ
I've uploaded the BSM_HQ observations from 2013 and 2014 to the AID. Not a very continuous set, as this telescope is used for testing, so it is down often and has had several different CCDs, filters and telescopes over that period of time. However, it does show that this is an interesting star with substantial variation throughout the year, not just from this recent outburst. I'd recommend placing it on your observing program in the future.
If you want to see the BSM_HQ data, use an 800-day light curve and highlight observer HQA. All of that submitted data has been transformed.
Arne
Looks like you've been pretty much a one-man-band up until this outburst. WTG, Arne!
Lew
Hi Lew,
Actually, BSM_HQ has been the one-robot band.
I put the target on the queue of BSM_HQ, and have been monitoring the results. I've submitted my analysis of the data to the AID, but Bart Staels is also looking at the data and has recently submitted the Ic observations that were also taken. In addition, Helmar Adler is the BSM_HQ Telescope Advocate, and is the person who opens and closes the facility on a nightly basis and monitors the data collection. Gary Walker has been keeping the enclosure working; Aaron Sliski does hardware and software maintenance; Matt Templeton has written the processing scripts and monitors the data processing; Elizabeth Waagen looks at all of the nightly images and judges quality. Therefore, the AG Peg dataset from BSM_HQ (and from any other AAVSOnet telescope) is far more of a team effort than people may realize!
Arne
Here is a low-resolution spectrum (R = c.700) of AG Peg I took last night.
The H-alpha emission line peaks at 14 times the continuum, but I've plotted the spectrum with a maximum Y of 5 to bring out some of the other line details.
Cheers
Jonathan
It concerns me to see the recent cluster of visual estimates placing this star between magnitude 7.5 and 7.7. Given the good selection of comp stars in this range it is difficult to see how some observers can find AG that faint, especially after all slightly earlier visual data had tightly clusters around the CCD-V values with minimal scatter at about half a magnitude brighter. This is one of those instances where it might have proven interesting if observers had reported what instrumentation they were employing to see if there might be some sort of correlation. In my opinion no one should be using anything more than ordinary binoculars to monitor AG visually at the present time.
J.Bortle (BRJ)
Hi all,
AG Peg has brightened still further, this morning it was brighter than 7.0 in V.
Douglas.