[vsnet-alert 24535] ASASSN-20jl is a new SU UMa (or WZ Sge) type dwarf nova

[Tonny Vanmunster tonny.vanmunster@gmail.com via vsnet-alert]

Dear colleagues,

As suspected by Taichi Kato, ASASSN-20jl indeed is a new SU UMa type dwarf
nova. I just examined 3hrs of unfiltered CCD observations obtained last
night (2020, Aug 13/14) at CBA Extremadura Observatory. I will publish a
detailed analysis of my findings later tonight, when I have also tonight's
observations available, but it looks like the superhump period is close to
0.0582d. The amplitude is still small (about 0.04 mag), put the typical
superhump profile is clearly present. I can't rule out that this still might
turn out to be a WZ Sge-type dwarf nova - let's collect more observations.

More news to come,

Best regards
Tonny  

--
Tonny Vanmunster
CBA Belgium Observatory
CBA Extremadura Observatory
www.cbabelgium.com
www.peranso.com
 

-----Original Message-----
From: vsnet-outburst
[mailto:vsnet-outburst-bounces at ooruri.kusastro.kyoto-u.ac.jp] On Behalf Of
Taichi Kato
Sent: donderdag 13 augustus 2020 8:14
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Subject: [vsnet-outburst 25498] ASASSN-20jl update

ASASSN-20jl update

   Is there anyone following this target?

ASAS-SN data:
https://asas-sn.osu.edu/light_curves/063bb5c4-6298-4640-85b4-03635ad12aab

   The light curve looks like to me a WZ Sge star (or less likely, a
background nova).  I suspect that the CV is a fainter (possibly unresolved)
companion of the V=14.7 mag star.  NUV=20.8 would be fine for a faint dwarf
nova in quiescence.  If this is indeed a WZ Sge star, the age may be
inconsistent with a G-type star (assuming that they are physically
associated).

   As judged from the light curve, it may be already superhumping if it is a
dwarf nova.  Spectroscopy is also desired (it was a pity that long rainy
season in Japan prevented observation).