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[vsnet-chat 9028] EW Hya (UG) and NSV19451
by Taichi Kato 25 Mar '22

25 Mar '22

EW Hya (UG) and NSV19451 EW Hya is an UG star. ASAS-SN data: https://asas-sn.osu.edu/sky-patrol/coordinate/635c2114-d4d3-4c00-b6b3-b1718… Several outbursts were recorded. 124005.624 -302818.49 (2000.0) Gaia_DR2_3470701018210385664 plx=1.335(0.592) dismod=9.4 pmra=-12.531(1.507) pmdec=-4.957(0.835) G=20.001 BP=20.068 RP=19.540 124005.624 -302818.49 (2000.0) Gaia_EDR3_3470701018210385664 plx=1.284(0.409) dismod=9.5 pmra=-12.695(0.523) pmdec=-5.659(0.284) G=19.835 BP=19.888 RP=19.458 124005.635 -302818.63 (2000.0) GALEX_DR5_6386854346909290646 NUV=19.967(0.100) FUV=20.152(0.245) NSV19451 https://istina.msu.ru/media/publications/article/4bb/965/2459689/ats1252.pdf According to this, the author noted a variable star near the position of EW Hya. The author was not sure about the identity with EW Hya because the recorded magnitude was much fainter than EW Hya. The author noted that UG type is not excluded. Considering the ASAS-3 behavior and magnitude, Kolevatykh indeed observed the UG star EW Hya and there is no other variable. NSV19451 = EW Hya. The 14th mag star (currently identified as NSV19451) is constant in ASAS-3: https://asas-sn.osu.edu/sky-patrol/coordinate/202e2dd6-426c-4e51-a315-97d55…

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[vsnet-chat 9027] ASASSN-21ob: dwarf nova below the period gap with strong ellipsoidal variation
by Taichi Kato 18 Mar '22

18 Mar '22

ASASSN-21ob: dwarf nova below the period gap with strong ellipsoidal variation From ZTF data. Porb = 0.0769268(3) d. Double-wave modulation (ellipsoidal variation). Total amplitude 0.14 mag. Too red for this Porb and the secondary may be evolved. Although genuine superoutburst has not been recorded, it is expected.

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[vsnet-chat 9026] ASASSN-21ls: dwarf nova below the period gap with strong reflection effect
by Taichi Kato 18 Mar '22

18 Mar '22

ASASSN-21ls: dwarf nova below the period gap with strong reflection effect From ZTF data. Porb = 0.0579261(1) d. The orbital profile looks like a detached subdwarf binary. There was indication of primary eclipse (but not sharp, probably due to the accretion disk). Total amplitude 0.58 mag. Too red for this Porb and the secondary may be evolved. Long outburst in 2021 June-July with rebrightenings. The overall type is UGSU:+R+E

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[vsnet-chat 9025] ASASSN-21dh: object below the period gap
by Taichi Kato 18 Mar '22

18 Mar '22

ASASSN-21dh: object below the period gap From ZTF data. I obtained a period of 0.0943185(3) d. Double-wave modulation (amplitude 0.25 mag). The color is red for this period and the secondary may be somewhat evolved.

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[vsnet-chat 9024] ASASSN-21ap: likely helium dwarf nova (superoutburst in 2021 Feb)
by Taichi Kato 18 Mar '22

18 Mar '22

ASASSN-21ap: likely helium dwarf nova (superoutburst in 2021 Feb) From ZTF data. Short initial outburst, rapid fading and rebrightening. Short rebrightening on a fading tail. All characteristic to an AM CVn-type superoutburst.

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[vsnet-chat 9023] ASASSN-15am: SS Cyg outbursts from a long-Porb binary
by Taichi Kato 18 Mar '22

18 Mar '22

ASASSN-15am: SS Cyg outbursts from a long-Porb binary Using the ZTF data, I obtained a period of 0.687879(3) d. This period was based on slight differences between maxima and minima within one cycle. Half a period (0.343939 d) gives a reasonable phased light curve but is not sinusoidal and I consider that the original period is correct. The amplitude is 0.27 mag. Outbursts were present both in ASAS-SN and ZTF data. The M_V of the outbursts (+6) is somewhat fainter than those of typical dwarf nova outbursts.

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[vsnet-chat 9022] VSOLJ Variable Star Bulletin no.96
by meineko 14 Mar '22

14 Mar '22

VSOLJ Variable Star Bulletin no.96 is now available. http://vsolj.cetus-net.org/bulletin.html No.96 WFI J161953.3+031909: eclipsing ER UMa-type and Z Cam-type star in the period gap Taichi Kato --------------- Seiichiro Kiyota VSOLJ

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[vsnet-chat 9021] BMAM-V625: IW And+E
by Taichi Kato 14 Mar '22

14 Mar '22

BMAM-V625: IW And+E From ZTF data. Heartbeat state in 2018. Long standstill in 2019.

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[vsnet-chat 9020] BMAM-V546: VY Scl+E
by Taichi Kato 14 Mar '22

14 Mar '22

BMAM-V546: VY Scl+E From ZTF data. Low state in late 2021 fainter than 21 mag.

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[vsnet-chat 9019] LV Vul: currently VY Scl state
by Taichi Kato 14 Mar '22

14 Mar '22

LV Vul: currently VY Scl state From ZTF data. Low states in 2018 and 2020 (g reaching 19.0). Currently in high state around g=16.7.

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