Gaia21efs: likely CV (dwarf nova?)
Tonny Vanmunster reported observations. The data
show 0.15 mag variations (flickering or part of
early superhumps?). The object is thus unlikely
a microlensing, but likely a CV. Spectroscopy is
OT J002656.6+284933 superoutburst
This object is known as an SU UMa star above
the period gap with multiple rebrightenings.
The last outburst was recorded in 2016.
YYYYMMDD(UT) mag observer
20211013.6632 <159c (Yutaka Maeda)
20211014.6574 <167c (Yutaka Maeda)
20211015.6572 <165c (Yutaka Maeda)
20211017.6568 <158c (Yutaka Maeda)
20211023.5999 154:c (Yutaka Maeda)
20211025.5847 153cG (Yutaka Maeda)
20211026.5832 152:cG (Yutaka Maeda)
20211027.5983 153:cG (Yutaka Maeda)
ASASSN-21tr: superhump period
Tonny Vanmunster, Tamas Tordai and Itoh-san have
reported observations. The superhump period since
Oct. 25 is 0.0666(2) d. The amplitude is still
small (0.06 mag) and they are most likely stage A
XM78HT: regular superhumps
The most recent data by Kyoto U. team on Oct. 26
detected clear ordinary superhumps. The superhumps
started growing on Oct. 25 (Vihorlat Obs. team).
The current period (stage A) is 0.05596(8) d.
I have been collecting unfiltered CCD observations of ASASSN-21tr over the
past several nights at CBA Extremadura Observatory, using a 0.40-m f/5.1
telescope and SX-46 CCD camera under (mostly) clear skies.
The collected light curves did not show obvious periodic modulations, with
the exception of last night Oct 25/26, 2021. Regular superhumps with an
amplitude of 0.11 mag are clearly visible, establishing ASASSN-21tr as a new
SU UMa-type dwarf nova. A period analysis using the ANOVA, Lomb-Scargle,
Generalized-Lomb-Scargle and PDM methods (Peranso 3.0), yields a combined
superhump period of 0.0647 +/- 0.0012d. The object was at mag CV = 15.4 on
I will send my observations to AAVSO, CBA and VSNET for further analysis.
CBA Belgium Observatory
CBA Extremadura Observatory
PERANSO : The Light Curve and Period Analysis Software