Excerpts from CBET 4811:
"Robert H. McNaught, Coonabarabran, NSW, Australia, has found an apparent 5th-magnitude nova on CCD images obtained on July 15.590 UT with a Canon 6D camera and an 8-mm-f.l. f/2.8 lens"
"... he obtained visual mag 5.3 with 2.3x40 opera glasses (using AAVSO A chart for MGAB-V207)."
http://www.cbat.eps.harvard.edu/iau/cbet/004800/CBET004811.txt (behind paywall)
Recent ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S and Kochanek et al. 2017PASP..129j4502K) light curve and data: https://asas-sn.osu.edu/light_curves/f55224a2-57e5-46b7-bb67-d354e29fc3…
MGAB-V207 20200702.183 16.56g ASN
MGAB-V207 20200702.186 16.33g ASN
MGAB-V207 20200704.189 15.51g ASN
MGAB-V207 20200708.171 6.78g ASN
MGAB-V207 20200708.172 6.78g ASN
MGAB-V207 20200708.173 6.77g ASN
The eruption apparently began already on 2020 July 4.
Spectroscopy, multiband photometry, and precise astrometry are urgently required.
According to ASAS-SN data this nova was already 6.7g' bright on 8th July. It would be worth to check archive photos made between 4th and 15th July.
Yes – see also an identical light curve and a list of recent ASAS-SN Sky Patrol observations in my initial posting.
Complete light curve and data at https://asas-sn.osu.edu/light_curves/24392057-8100-449a-9b49-7160d6c7b4…
"From the complete ASAS-SN lightcurve, the brightening in ASAS-SN data on July 4 seems to be part of the normal variations for this object, while on July 8 it is definitely a nova."
Actually we cannot say it for sure. MGAB-V207 rarely was as bright as gmag. 15.5 in ASAS-SN Sky Patrol data.
Keep in mind that ASAS-SN mangitudes are saturated for such a bright object. So we know it was bright but not exactly if it was on the rise or at maximum.
I also think that 15.5 g might be the beginning of the outburst already.
AAVSO Alert Notice 711 reports on the discovery of the nova outburst of MGAB-V207 = N Ret 2020. Please see the notice for details and observing instructions.
This object has threads in the following forums: Time Sensitive Reports, Novae, and Cataclysmic Variables. To stay informed about it, subscribe to these threads (option 1 below under Subscribe in each thread) - see comments and questions from observers, information about any campaigns on it, and notes from AAVSO HQ. Add a post yourself - join in the discussion!
Many thanks, and Good observing,
Elizabeth O. Waagen, AAVSO HQ
Excerpt from CBET 4812:
"R. H. McNaught, Coonabarabran, NSW, Australia, forwards the following pre-discovery V magnitudes from all-sky video images taken by M. A. Phillips at the Edward Pigot Seismic Observatory, Coonabarabran, using a
ZWO ASI178MC-COOL color CMOS camera and a 1.4-mm-f.l. f/1.8 fish-eye lens: July 6.81, [6.0; 7.79, [5.5; 8.78, 5.4; 11.76, 3.7; 12.8, 3.8; 13.83, 4.0; 14.8, 4.4; 15.8, 4.7."
http://www.cbat.eps.harvard.edu/iau/cbet/004800/CBET004812.txt (behind paywall)
I am part of a group that distributes information about potential multi-instrument simultaneous observing opportunities. As part of this group, I saw an alert about NuSTAR observations of this source. Since I am not directly involved with this science, I'm not sure how useful simultaneous X-ray + optical observations are. But in case they are I wanted to post the planned observation times.
This translates to July 17, 2020 (tonight) from 23:35:16 UTC to July 19, 2020 10:45:00.
I am hopeful the people more directly involved with this outburst can comment on potential research applications and collaboration between professional astronomers and AAVSO members/observers.
thank you for posting this! It was me who triggered the NuSTAR observation of MGAB-V207. Silly enough, it just didn't cross my mind that it would be good to announce the exact observing time here, I'm very sorry about that!
I confirm that observations of all kinds (visual, DSLR, CCD, PEP) during the time of NuSTAR exposure will be especially useful. With these observations we'll be able to measure the nova brightness simultaneously in gamma-ray (Fermi/LAT is observing), X-ray (NuSTAR) and optical that would help to constrain theoretical models of nova emission (and specifically the role shock waves play in producing optical light of the nova). It would also be interesting to see the shape of the optical lightcurve within the NuSTA observing window to see if there are any correlated optical/X-ray changes.
Observations before and after the NuSTAR exposure are also very useful to put things in context: see if there is any fast variability on top of the usual nova lightcurve (that might be an indication of shocks) and measure the nova decline time by 2 and 3 magnitudes (t_2, t_3 - parameters related to the energetics of the outburst and useful to compare novae to each other).
Please, observe this nova if you can and report your mesurements to the AAVSO database!
2020-10-10 (01:41 UT)
Photo by L.A.R. Araujo
Image: North > left; East > down