19 March 2021 at 9:56 am #574917
Yuji Nakamura (Kameyama, Mie, Japan) has reported the discovery of a possible nova, PNV J23244760+6111140, on March 18.4236
Tonny Vanmunster confirmed the transient later that day at V = 8.95 +/- 0.03 (CBA Extremadura Observatory using a 0.40-m f/5.1 telescope and SX-46 CCD camera)
ATel #14471 reports spectroscopic classification of the object as a classical nova (Hiroyuki Maehara (National Astronomical Observatory of Japan), Kenta Taguchi (Kyoto University), Yusuke Tampo (Kyoto University), Naoto Kojiguchi (Kyoto University), Keisuke Isogai (Kyoto University).
Nova Cas 2021 is at RA 23 24 47.73 Dec +61 11 14.8 (J2000.0)
This is a bright nova and further observations are encouraged. The field is circumpolar from UK and it should be a binocular object. Charts and sequences are available from the AAVSO Variable Star Plotter.19 March 2021 at 1:13 pm #583961
Robin makes an important point here about alert systems. There are many such available.
One that might be of interest to BAA Members is the BAA VSS Alert Group. You can find out how to sign up here.
The aims of the group are to distribute information on variable vtar activity currently observed by BAA VSS members. The Nova discovery was announced there.
Hope you get some more clear sky, Robin!19 March 2021 at 1:24 pm #583960Robin LeadbeaterParticipant
It was clear last night here too and I was looking round for interesting targets for spectroscopy. This would have shot to the top of the list but nothing on vsnet-alert. Where better should I be monitoring ?
EDIT: I see it is on vsnet-alert. My brain did not register the alerts for some reason I think I must have thought Cze was some obscure southern constellation and moved on. 🙁
Robin19 March 2021 at 7:31 pm #583963
Attached stack of 11x1s shows it around 7.6 unfiltered (Gaia G reference) just now (Mar 19.80).19 March 2021 at 7:56 pm #583964Lars LindhardParticipant
Here is a single-shot image from tonight with Canon 77d through a 14″ SCT exp. 15 sec. iso 3200.19 March 2021 at 8:05 pm #583965
The astrometry I get using Gaia DR2 is 23:24:47.70 +61:11:14.8 with a very high SNR and 1.29 arcsec/pix sampling. There are four stars within 5″ in Gaia DR3. The closest to that position is 15.36G offset by 0″.47 in RA, 0″.04 in Dec.19 March 2021 at 8:30 pm #583966
Did you get the binoculars out, Nick?19 March 2021 at 9:18 pm #583967
Yes, and I can see it just below M52. I’m not sure about making a magnitude estimate though!19 March 2021 at 9:48 pm #583968Mike HarlowParticipant
Quick look low resolution spectrum. Reveals a bright continuum with strong hydrogen emission lines and some other as yet unidentified emission lines. Field is 12 x 6 arc minutes and conveniently includes an ‘ordinary’ A-type star spectrum for comparison(!) with hydrogen absorption lines. Taken with a 26cm, 3 degree objective prism on a 12inch F/3.6 astrograph. 24 x 20 seconds. 19th March 2021 at ~21:00GMT.19 March 2021 at 10:58 pm #583969David BoydParticipant
This spectrum of Nova Cas 2021 was recorded with a LISA spectrograph on a C11 during a short break in generally overcast skies tonight. It shows strong emission lines of the hydrogen Balmer series and He I. There are P Cygni profiles extending to around -2500 km/s relative to the rest wavelength on all emission lines. The spectrum was calibrated in absolute flux using currently recorded B and V photometry which gave V = 7.77+-0.04 and B-V = 0.50.
David20 March 2021 at 9:25 am #583970
CBET 4945 designates this nova as V1405 Cas. My image of it and M52 which is a degree to the north is here.20 March 2021 at 11:36 am #583972Mary McIntyreParticipant
On Tuesday 16th March I was imaging Caroline’s Rose in Cassiopeia with a 50mm lens, so I had a wide enough field of view that the area around Nova Cas was in shot. In my stacked image I can just see a tiny star in the right place according to the finder chart circulated by the SPA, just above HIP 115566. It would have been much fainter back on 16th, I really hope to get another shot to compare it in the next few days. The attached photo was taken with a Canon 1100D with 50mm fixed lens. It’s a stack of 280 x 8 seconds. I’ve included an inverted version as well.
www.youtube.com/user/Spiceyspiney20 March 2021 at 1:33 pm #583973Paul G. AbelParticipant
Well I’ve printed off the comparison chart, and I have the RA and Dec ready to go- just need a clear sky tonight!20 March 2021 at 1:35 pm #583974Martin MobberleyParticipant
I took some pre-dawn images via T11 at New Mexico (0.51m CDK) a couple of hours ago. The ‘pretty pic’ unfiltered 120 sec image is here.
I also took some much shorter V filtered images. The brightest pixels in the nova disc were 30% of the way to saturation in a 5 second V shot.
Using the AAVSO chart’s somewhat dimmer mag 9.0 and 9.1 stars gives a V mag of 7.70 at 11:45 UT this morning (Mar 20). JD = 2459293.98958.
Martin21 March 2021 at 8:52 pm #583987Pierre GirardParticipant
I imaged the field last night March 20 at 1939UT. Not having access to the sequence I used the manitudes of field stars on Stellarium giving an estimate for the Nova of Magntude +7.7 . Image attached. Details on Image.21 March 2021 at 10:47 pm #583988David SwanParticipant
Wow, it’s bright – and so nicely placed in Cas next to M52 and the Bubble Nebula! I carried out a 41 x 5s stack this eve: not scientifically useful, but a pretty pic, I think.22 March 2021 at 5:42 am #583991Andrew ReadParticipant
In Cassiopeia! Would that it could have waited a year until the 450’s anniversary of Tyco’s Nova of 1572.
If you like costume drama historical documentaries, this one about Johannes Kepler, including his time with Tycho Brahe, is quite excellent:
(in case it’s cloudy when you go outside to look for the new nova of 2021)22 March 2021 at 7:24 am #583992Terry McKnightParticipant
I was struggling to find it with binos but was imaging the coordinates in a brief cloudless window of opportunity and managed 7 six minute subs which I still have to process. Here is a rough image straight out of EKOS.22 March 2021 at 2:32 pm #583993Terry McKnightParticipant
Here is my cleaned up version. I had to shoot it in Ha with my ASI183MM with the WO ZS103. Processed with PixInsight and Photoshop.
7 x 360 second subs and then it clouded over!22 March 2021 at 4:18 pm #583994Daryl DobbsParticipant
Nice picture, is that the nebulosity around the Bubble Nebula coming into view at the bottom. I managed to spot it during a brief break in the clouds through binoculars
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