- vsnet-newvar - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-newvar 9126] ASASSN-22dq: new WZ Sge-type dwarf nova
by Taichi Kato 22 Mar '22

22 Mar '22

ASASSN-22dq: new WZ Sge-type dwarf nova Tamas Tordai has reported observations. The data show 0.08-mag early superhumps (double maxima) with a period of 0.0561(8) d. ASASSN-22dq --- ------- 5:45:45.28 59:54:32.6 2022-03-19.29 13.65 SDSS DSS VIZIER ------- CV candidate, matches to PS1 g=20.0, g>16.7 on 2022-03-17.29, g=13.9 on 2022-03-19.29, g=14.6 on 2022-03-21.29 ASASSN-22dq 20220317.29 <167g ASN ASASSN-22dq 20220319.29 139g ASN ASASSN-22dq 20220321.29 146g ASN 054545.231 +595432.09 (2000.0) Gaia_DR2_282141555636377984 plx=2.781(0.664) dismod=7.8 pmra=0.263(0.611) pmdec=-2.593(0.740) G=19.746 BP=19.905 RP=19.273 054545.231 +595432.09 (2000.0) Gaia_EDR3_282141555636377984 plx=2.668(0.440) dismod=7.9 pmra=-0.451(0.272) pmdec=-2.094(0.321) G=19.707 BP=19.850 RP=19.333 No past outburst in the ZTF data.

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[vsnet-newvar 9125] ASASSN-22dr
by Taichi Kato 22 Mar '22

22 Mar '22

ASASSN-22dr ASASSN-22dr --- ------- 10:54:17.35 -82:47:14.8 2022-03-20.13 12.89 SDSS DSS VIZIER ------- CV candidate, matches to GAIA DR2 G=20.8, g> 16.9 on 2022-03-18.17, g=15.9 on 2022-03-19.08, g=13.3 on 2022-03-20.12, g=13.6 on 2022-03-21.20 ASASSN-22dr 20220318.17 <169g ASN ASASSN-22dr 20220319.08 159g ASN ASASSN-22dr 20220320.12 133g ASN ASASSN-22dr 20220321.20 136g ASN 105419.470 -824717.58 (2000.0) Gaia_DR2_5197523925585449344 plx=3.619(1.273) dismod=7.2 pmra=-12.461(1.793) pmdec=6.315(2.095) G=20.655 BP=20.847 RP=19.181 105419.467 -824717.58 (2000.0) Gaia_EDR3_5197523925585449344 plx=2.479(0.946) dismod=8.0 pmra=-11.265(1.286) pmdec=6.210(1.473) G=20.585 BP=21.483 RP=19.301 105418.084 -824716.39 (2000.0) GALEX_DR5_6386748728292672066 NUV=22.218(0.444) FUV=-(-) No outburst in ASAS-3.

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[vsnet-newvar 9124] Gaia22ayj: outburst from ultrashort period binary?
by Taichi Kato 22 Mar '22

22 Mar '22

Gaia22ayj: outburst from ultrashort period binary? ZTF data recorded time-resolved photometry on 2019 Jan. 10. The data show very clear double-wave modulations with a period of 0.006500(7) d. Using this period, I analyzed the entire ZTF data and found a period of 0.006499102(1) d = 9.4 min. The profile looks like that of a beta Lyr star with the primary and secondary eclipses of 1.5 and 0.7 mag. Although the period could be that of the spin period of the white dwarf, the amplitude is too large and the profile is too stable. The profile very much looks like an eclipsing binary and the period may be the orbital period. The period is, however, surprisingly short. The value is close to that of the direct impact AM CVn-type accretor V407 Vul (0.006590 d). Gaia22ayj showed an outburst (mag 16 in early March and may be still ongoing) and it suggests the presence of an accretion disk. Could it be a pre-AM CVn object? 082526.528 -223212.35 (2000.0) Gaia_DR2_5697000580270393088 plx=0.601(0.381) dismod=11.1 pmra=-4.255(0.538) pmdec=2.477(0.370) G=19.241 BP=19.399 RP=18.345 082526.528 -223212.34 (2000.0) Gaia_EDR3_5697000580270393088 plx=0.430(0.220) dismod=11.8 pmra=-4.238(0.206) pmdec=2.636(0.171) G=19.216 BP=19.570 RP=18.461

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[vsnet-newvar 9123] ASASSN-22dl: eclipses
by Taichi Kato 19 Mar '22

19 Mar '22

ASASSN-22dl: eclipses Josch Hambsch and Itoh-san have reported new observations. The object already show eclipses at least since Mar. 18. It may have already entered a phase of ordinary superhumps (now stage A).

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[vsnet-newvar 9122] ASASSN-21ob: dwarf nova below the period gap with strong ellipsoidal variation
by Taichi Kato 17 Mar '22

17 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-newvar 9121] ASASSN-21ls: dwarf nova below the period gap with strong reflection effect
by Taichi Kato 17 Mar '22

17 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-newvar 9120] ASASSN-21dh: object below the period gap
by Taichi Kato 17 Mar '22

17 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-newvar 9119] ASASSN-21ap: likely helium dwarf nova (superoutburst in 2021 Feb)
by Taichi Kato 17 Mar '22

17 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-newvar 9118] ASASSN-15am: SS Cyg outbursts from a long-Porb binary
by Taichi Kato 17 Mar '22

17 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-newvar 9117] ASASSN-15rs superoutburst
by Taichi Kato 17 Mar '22

17 Mar '22

ASASSN-15rs superoutburst YYYYMMDD(UT) mag observer 20220307.5176 <160c (Yutaka Maeda) 20220308.492 175C (Mitsutaka Hiraga) 20220308.5174 <163c (Yutaka Maeda) 20220309.5193 <153c (Yutaka Maeda) 20220310.5125 <145c (Yutaka Maeda) 20220312.4952 142:cG (Yutaka Maeda) 20220315.5073 <133c (Yutaka Maeda) 20220315.5319 146C (Masayuki Moriyama) 20220316.5009 143cG (Yutaka Maeda) 20220316.5009 143cG (Yutaka Maeda)

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