Affiliation
American Association of Variable Star Observers (AAVSO)
Sat, 07/07/2012 - 15:29
The CBAT Transient Object Follow UP page reports the discovery and observations of yet another probable nova in SGR, as indicated here:
http://www.cbat.eps.harvard.edu/unconf/followups/J18202726-2744263.html
J.Bortle (BRJ)
The nova is almost too bright! Observed last night (early this morning actually), and visually think 7.5, took CCD image, but saturate at just about 2 seconds, no other bright stars nearby in field (10.5 brightest standard to compare to). tonight I will take the camera off the 32 inch, put it on a six inch scope, for wider field and try and get better comparison stars.
really bright nova!
Mario Motta
BSM-South (thanks, Peter!) has obtained a BVRI dataset for this new nova. I've posted on
http://www.aavso.org/tmp3/nsgr2012_4v.jpg
a 30x30arcmin finding chart for this object. Note that it has a close companion that will be a problem as it fades.
A rough analysis indicates:
2012-07-08 14:37UT V=8.07 B=8.44 (B-V) = 0.37
so this one is not heavily reddened. There are several bright possible sequence stars, but this is a crowded field, so be aware of blended stars and problems as the nova fades.
Arne
APASS-south observed the field containing this nova on:
2011/04/30 nonphotometric
2012/03/30 photometric
2012/03/31 nonphotometric
2012/07/08 photometric
(UT dates) where the last date is of course saturated. No detection was seen on the three pre-outburst nights at the automated plate limit of V=16.5. I'll look at the original BVgri images when time permits to see if a fainter precursor can be seen. Now that we have multiple-epoch observations for most of the sky, we can data-mine for such events.
Arne
Just a note for observers of this nova. The 125 comp star is RR LYR variable V1288 SGR. I had labeled this as the 128 comp star earlier. Sorry. Kevin - PKV
Thanx, Kevin for calling our attention to it. I wrote to the Sequence Team list, asking Mike to remove this 'comp star'.
Hi, Kevin et al.,
It turns out that V1288 Sgr was misidentified in the GCVS and in VSX. My mistake was to choose the comp stars based on their constancy and "uncrowdedness" but without checking their ID.
Due to your comment on the star's ID and the fact that I had checked it was constant, we were able to correct another wrong identification.
The actual V1288 Sgr is a star 35" to the North of the former candidate. It is 23" to the W of a 14.3 mag. star. It varies from 13.4 to 14.5 or so.
The 125 comp star is just outside the contamination limit in the smallest ASAS aperture (25-30" or so) so the magnitudes were okay and data from CMC14 and UCAC3 were used to confirm its value.
Maybe the proximity of the RR Lyrae and the 143 (red) star may be a problem visually if not enough magnification is used but I think that at 13-14th magnitude, high powers are in order.
The nova is only 1.36 arcminutes away from V1288 Sgr.
Cheers,
Sebastian
Sebastian, Thanks for the quick correction and update. I noticed the overlap of V1288 SGR and the 125 comp star in VPHOT. All is correct in VPHOT now. Now, I need to redo my reductions for V1288 SGR. Thanks.
Kevin - PKV
Continuing with the corrections, there is a new confirmed mira in the field that has changed identification.
NSV 10632 was catalogued at 18 20 18 -27 49 38 (J2000.0).
But it was 1'.08" away at 18 20 21.64 -27 50 26.1.
It ranges from 12.3 to <14.2 every 209 days.
It is 4'.8" South of the nova. So you have two more variable stars to observe with completely new identifications.
Cheers,
Sebastian
I'm a complete newbie. But I just got some BRVI data (10 seconds) at SSO 24". It is bright indeed.
Having fun!
Jason
I would like to know if data relevant to the field near this new nova are already available on the APASS survey. Two days ago I tried for a filed of view of about 0.2 deg, but I did not get any data.
Thank you in advance.
Alessandro Maitan
Hi Alessandro,
As I mentioned in this thread yesterday, APASS has observed this field on four occasions. Unfortunately, at the time DR6 (the current release) was created, only three observations had been made and two of those were deemed non-photometric. Since two photometric observations was the main criteria for inclusion in DR6, this field does not appear in DR6. I expect it to be in DR7, but that will be a couple of months from now.
Arne