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AY Lac

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garypoyner's picture
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AY Lac

This object (catalogued as a NR or UGWZ - Recurrent Nova or Dwarf Nova of the WZ Sge type) has been detected in outburst by ASAS-SN on Oct 08.283 at 13.83g. Only two previous outbursts have been recorded, 1927 & 1966.   

It's position is RA 22 22 22.10   Dec +50 23 40.0

Photometry, astrometry and spectroscopy are urgently required.   Please report your observations to BAAVSS and/or AAVSO.

A finder chart can be obtained from the AAVSO Chart Plotter here

Gary

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Just observed:

Just observed:

AY Lac Oct 8.778 13.83C

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AY Lac

An image of the nova. Lots of stars around here!

Image details: Centre RA 22h 22m 32.3s,  Dec +50° 23' 42.5"; Pos Angle +316° 35.2'; FL 196.3 mm; 2.52"/Pixel

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Indeed. A very starry field.

Indeed. A very starry field. I get a position of 22 22 22.17 +50 23 40.0 (J2000) using Gaia DR2.

Robin Leadbeater's picture
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Spectrum

ALPY 600 ~12A resolution. A blue continuum with weak Balmer absorption

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AY Lac observed

Gary, thanks for the heads up. I made it (visually) mag 13.9 on 2020 Oct 9 at 01:38 UT. I used the AAVSO chart.  Yes, it is a rich field, but easy enough.

John

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AY Lac

Good to see reports of AY Lac coming in, and that the outburst coincided with clear sky for some people - me included.   I had AY Lac varying between 13.8-14.1 visually over several hours, but after spending decades looking at empty space it was a thrill just to see it.

Gary

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Previous outbursts

Hi Gary,

Interesting stuff.  Any references to the previous outbursts available online?  Curious to known if the 1927 and 1966 outbursts evolved in the same way or were they significantly different from each other?

Thanks,

Mike.

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Re: Previous outbursts

Hi Mike,

Not a lot available, but this is interesting...

https://konkoly.hu/pub/ibvs/5401/5441.pdf

Gary

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AY Lac (unfiltered)

I did my first variable star measurement in 30 years.

Result: 20201009 01:27 Mag=14.1 (first crude estimate using AAVSO) while AA7 says 13.94. What does everyone else use?

Refined result using Gaia DR2 plus another from the following night... 

20201009 01:27 2459131.60262 14.05

20201010 00:21 2459132.51466 14.30

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A little fainter last night:

A little fainter last night: Oct 9.852 at ~14.17C

Robin Leadbeater's picture
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fading

A short clear spell tonight. Not long enough to get a spectrum but off the spectrograph guider it looked about a magnitude fainter than on 8th  

garypoyner's picture
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fading

I had it 15.0 visual this morning (13th).  

I was hoping that it might do more (we have waited rather a long time to see it after all!).   I don't see any evidence for superhump like features in the light curve at all.   Perhaps it might surprise us with a second outburtst once it's faded further.

One of the earlier interpretations of it's class is Recurrent Nova.   Maybe?

Gary

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Dwarf or Recurrent

Interesting. The spectrum seems consistent with a dwarf nova outburst. I managed to salvage a couple of short exposure spectra from aborted runs on the 10th and 12th. They are very noisy though so the only significant feature is the hot continuum shape.

Robin

 

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Another spectrum

Another spectrum on a better night (2hr 20min exposure at mag ~15.5 The limit at this resolution).   Not much happening compared with a week ago

https://britastro.org/specdb/data_graph.php?obs_id=8021%2C8002&multi=yes

Robin