[vsnet-alert 24691] ATLAS20yzy (= ASASSN-20lf, ZTF20abypgvs, AT 2020spm)

Wed Sep 16 03:05:43 JST 2020

 Dear fellow observers,

Please note that the VSX primary name for this dwarf nova
(superoutburst) has been changed (ATLAS reported the
transient three days before ASAS-SN, see TNS reference):
https://www.aavso.org/vsx/index.php?view=detail.top&oid=1547456

As Shibata-san writes, further time-resolved photometry
is encouraged.

Clear skies,
Patrick
-------
     Am Dienstag, 15. September 2020, 16:10:45 MESZ hat Masaaki Shibata <mshibata at kusastro.kyoto-u.ac.jp> Folgendes geschrieben:  

 ASASSN-20lf: the emergence of superhump

Itoh-san, Moriyama-san, Tonny Vanmunster. and Kyoto Univ. observatory have
reported the observations for ASASSN-20lf (=ZTF20abypgvs).

The observations by Kyoto Univ. observatory on 14th Sep. showed a superhump
with a period of 0.0561(3) d and an amplitude of ~0.15 mag.
The first detection was 2020-09-04.24(UT) and the magnitude was 15.26(V)
mag. Because of the large outburst amplitude and the long delay time(10
days) of superhump appearance, this object is a good candidate for WZ
Sge-type star.

The entire ASAS-SN light curve is available at
https://asas-sn.osu.edu/light_curves/8ecd0c58-506b-4e14-a9e8-6d4ccf64bae8
<https://www.google.com/url?q=https://asas-sn.osu.edu/light_curves/8ecd0c58-506b-4e14-a9e8-6d4ccf64bae8&sa=D&source=hangouts&ust=1600263864223000&usg=AFQjCNEndwsq2DBmulk6k-c0Ad5vbZCtxQ>
.

More observations will clarify the period.