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PQ And - a very rare outburst

PostPosted: Fri May 29, 2020 10:17 am
by Robin Leadbeater
-----Original Message-----
From: Taichi Kato
Sent: Friday, May 29, 2020 1:34 AM
To: suuma@yahoogroups.com ; variable_star_forum@yahoogroups.com ; vsnet-alert@ooruri.kusastro.kyoto-u.ac.jp ; vsnet-alert@yahoogroups.com ; vsnet-campaign-dn@ooruri.kusastro.kyoto-u.ac.jp ; vsnet-outburst@ooruri.kusastro.kyoto-u.ac.jp ; vsnet-outburst@yahoogroups.com ; wzsge@yahoogroups.com
Subject: [vsnet-alert 24303] Re: PQ And in outburst!

Re: PQ And in outburst!

> PQ And in outburst!

This is, of course, of utmost importance.
This object was discovered as Nova And 1988 and
the current outburst nearly 32 years after the previous one!

According to IAUC 4620,

http://www.cbat.eps.harvard.edu/iauc/04600/04620.html

Information received some weeks ago indicates that a spectrogram
was obtained of D. McAdam's variable in Andromeda (IAUC 4570, 4577,
4579) with the 2.5-m Isaac Newton Telescope, La Palma, on Apr. 1, but
various computer problems have prevented recovery of the data. A
preliminary inspection of the object's spectrum at the time apparently
showed the presence of strong O III emission.

So the spectrum in outburst was present only in
observer's memory. It is the time to take a solid one!

The object is almost certainly a WZ Sge star and
was suggested to be a period bouncer (Patterson et al. 2005).
Observations of early superhumps and growth of ordinary
superhumps are extremely important (in the morning short
observing window).

There were only few observers who visually witnessed
the 1988 outburst (I was among them). So get up early
and add this object to your "life list" of outbursting
dwarf novae (such concept is called "lifer" in birding).

Re: PQ And - a very rare outburst

PostPosted: Mon Jun 01, 2020 4:46 pm
by Robin Leadbeater
I managed a couple of spectra taken under very extreme conditions, mag 10.5 in a bright summer night sky at just 5 deg altitude (air mass 10 !)

pqandoptbinweighted_20200529-30_Leadbeater.png
pqandoptbinweighted_20200529-30_Leadbeater.png (66.24 KiB) Viewed 1244 times


There is not much in common between them apart from the hot continuum so I suspect the smaller scale features are just noise

This was the setup

PQAnd_observing.jpg
PQAnd_observing.jpg (97.63 KiB) Viewed 1244 times


and this is a (reduced scale) raw spectrum image (note the curvature in the spectrum due to atmospheric refraction)

PQAnd_5x300s.png
PQAnd_5x300s.png (107.64 KiB) Viewed 1244 times


As an experiment I went even lower and observed 58 And at air mass 16 (2.5 deg Alt) This was the instrument response (including tellurics) at that air mass compared with a more typical curve. As well as the usual O2, H2O telluric bands, the overall broad dish shape in the response and the features either side of ~5850A caused by the Chappuis ozone absorption band are particularly noticeable

_58and_20200529_933_instresp_airmass_16.png
_58and_20200529_933_instresp_airmass_16.png (10.98 KiB) Viewed 1244 times



Cheers
Robin

Re: PQ And - a very rare outburst

PostPosted: Wed Jun 03, 2020 4:51 pm
by Robin Leadbeater
A professional spectrum has now been published taken 2020-06-03 which shows a typical dwarf nova spectrum ( Broad Balmer absorption lines with superimposed narrow emission lines)

http://www.astronomerstelegram.org/?read=13776

Although noisy, my rectified spectrum for 2020-05-30 (red) overlaid on the published spectrum (black), shows H alpha emission present and a hint of the H beta absorption with an emission core

PQ_And_black_atel13776_20200602_red_THO_20200530.png
PQ_And_black_atel13776_20200602_red_THO_20200530.png (28.28 KiB) Viewed 1192 times


Cheers
Robin