9 August 2021 at 1:24 am #575025Gary PoynerParticipant
There are reports that the recurrent Nova (NR) RS Oph is in outburst on the evening of Aug 8 at mag 5, having been at magnitude 11.2 on Aug 7 (of course, it’s cloudy in Birmingham).
EDIT. Aug 09 00:41UT. The outburst has now been confirmed by several observers.
Gary9 August 2021 at 9:37 am #584577
Here is a VSS light curve from the 2006 eruption:9 August 2021 at 10:33 am #584578Paul LeylandParticipant
I measured it at V=11.016 ± 0.005 at JD 2459431.4507
It’s been cloudy ever since. Unusual in these parts for this time of year.
Perhaps tonight …9 August 2021 at 10:37 am #584579
A series of spectra from 2006 taken using a Star Analyser.
I expect there will be many more spectra this time
Robin9 August 2021 at 1:07 pm #584580Ernesto GuidoParticipantWe performed some follow-up of RS OPHIUCHI 2021 outburst through a TEL 0.1-m f/3.6 astrograph + CCD located in the Heaven’s Mirror Observatory, Australia (MPC code Q56) and operated by Telescope Live network.
On images taken on August 09.42, 2020 we can confirm the presence of an optical counterpart (approximate R-filtered magnitude about +4.8; images were saturated in 10-second exposures) at coordinates:
R.A. = 17 50 13.20, Decl.= -06 42 28.2
(equinox 2000.0; UCAC4 catalogue reference stars for the astrometry).
Our image is available here: https://tinyurl.com/rsoph2021 or belowWith kind regards,Ernesto Guido, Marco Rocchetto & Adriano Valvasori9 August 2021 at 3:22 pm #584581Martin MobberleyParticipant
I’ve uploaded an image taken 1 hour ago to my community pages:
Martin9 August 2021 at 5:14 pm #584582
Atel 14838 from a team at Kyoto U report low resolution of RS Oph showing “Fe II, O I, and prominent Balmer lines. All of them listed here have a P Cygni profile. The velocity of the Hβ emission line is ∼ 2600 km/s. The profile and velocity indicate that this outburst is indeed a nova eruption, as is expected.”10 August 2021 at 12:33 am #584586David BoydParticipant
Here is a spectrum of RS Oph in outburst taken tonight, 9th August, with a LISA. Very sharply peaked H-alpha line with FWZI of about 7000 km/s. Other Balmer lines similarly broad, all with P Cygni absorption dips. I don’t remember seeing a spectrum quite like this before!
David10 August 2021 at 11:57 am #584590Daryl DobbsParticipant
Visible without binoculars but only just through the light pollution from Newport and Cardiff. Patchy cloud and nova was going behind trees when a patch cleared sufficiently for me to get an observation in. Then I had to balance on top of a wall holding my 20×80’s, our elderly neighbour seemed surprised! After 5 years living here she hasn’t got used to an amateur astronomer living next door. I’ll upload to database later.
Nice to see another bright Nova appear10 August 2021 at 3:07 pm #584589
This is only the start! (The narrow unshifted feature comes from the circumsystem material from previous outbursts). If it follows earlier outburst there is lots more strangeness to come. Watch for highly ionised coronal lines (like [Fe X, XI, XIV] and [A X] etc) produced as the shock heats the gas to 1 million K plus. There is an interesting account of taking spectra early in the 1958 outburst by George Wallerstein in the 2005 S&T article.
Robin10 August 2021 at 3:36 pm #584591
“The narrow unshifted feature comes from the circumsystem material from previous outbursts”
Correction that should be ….from interaction with the relatively slow moving red giant wind. This looks a good reference for the evolution of the optical spectrum in the 2006 outburst
Robin11 August 2021 at 8:34 am #584593Hugh AllenParticipant
Amazing to have a hat trick of bright novae, and the latest such an anticipated event. The weather here in Somerset has been poor this last few weeks but in murky conditions I was able to capture RS Oph last night, just 20 minutes after Robin’s spectrum in the BAA spectroscopy database. There is good agreement between our two spectra, both captured with an Alpy 600. Compared to David’s spectrum from the previous night (higher resolution LISA spectrum), there has been a significant increase in the relative intensity of the emission lines but is this due mostly to a decline in brightness of the nova?
Hugh11 August 2021 at 11:26 am #584594
There is an absolutely stunning high resolution echelle spectrum covering 3750-9300A in the BAA database from Joan Guarro Flo taken 20210809.838 using an amateur designed (by Tim Lester) home built remotely operated instrument. (zoom in to view the narrow P Cygni lines from the stellar wind superimposed on the broad nova ejecta lines) An impressive example of the progress in amateur spectroscopy since the last outburst.
Robin11 August 2021 at 2:12 pm #584595Paul LeylandParticipant
That is very impressive! I also love how the vibrational structure of the telluric molecular bands is so well resolved.11 August 2021 at 6:53 pm #584596Philip MasdingParticipant
A nice clear evening came along just at the right time much to my surprise. Some fascinating links and images on this page. Thanks to all11 August 2021 at 7:13 pm #584597
Still bright, but on the turn. Do try and observe if you can.12 August 2021 at 8:58 am #584599Alun HalseyParticipant
Here is my attempt at RS Oph on the night of the 10th using my C9.25 and Lhires III (23 micron slit) to collect nine 60 second images,chose Vega as my reference star.
Alun12 August 2021 at 10:59 am #584600Paul G. AbelParticipant
It looks like we may FINALLY get some clear skies here tonight- looking forward to making a magnitude estimate of it!13 August 2021 at 9:22 am #584601Alun HalseyParticipant
Acquired another spectrum last night (12th) using Lhires III and C9.25. Acquisition time of 21 minutes (7x180sec) with 23 micron slit.
Alun13 August 2021 at 1:31 pm #584602David BoydParticipant
The continuum flux level of the spectrum is dropping as the magnitude fades, V=4.88, 5.44, 6.24 for the 3 spectra below.
In answer to Hugh’s question above about the changes which have been taking place in the Balmer emission lines, I have posted information about this on the ARAS Forum at
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