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

[vsnet-newvar 9799] MGAB-V240: standstill interrupted by fading (AM CVn?)
by Taichi Kato 20 Feb '23

20 Feb '23

MGAB-V240: standstill interrupted by fading (AM CVn?) Using ZTF data in 2022, I noticed that a standstill was interrupted by up to 2 mag short fading at least four times. The object became brighter (for a short time) after such events. The fading rates exceeded 1 mag/d in some cases and this object may be an AM CVn star. If this identification is correct, repeated regular outbursts before 2020 were superoutbursts (with a supercycle of about 10-15 d). Faint, but unusual object.

1 0

[vsnet-newvar 9798] MGAB-V300 outburst (suspected AM CVn)
by Taichi Kato 20 Feb '23

20 Feb '23

MGAB-V300 outburst (suspected AM CVn) YYYYMMDD(UT) mag observer 20230218.5603 15.430zr (ZTF Alert DC mag (Masci+ 2019)) 20230218.5627 15.369zr (ZTF Alert DC mag (Masci+ 2019)) 20230218.5652 15.425zr (ZTF Alert DC mag (Masci+ 2019))

1 0

[vsnet-newvar 9797] TCP J17562787-1714548
by Taichi Kato 20 Feb '23

20 Feb '23

TCP J17562787-1714548 http://cbat.eps.harvard.edu/unconf/followups/J17562787-1714548.html The quiescent counterpart 2MASS 175627.896 -171453.26 (2000.0) 15.474 13.516 13.211 175627.901 -171453.72 (2000.0) Gaia_DR2_4144602552564272000 plx=0.198(0.244) dismod=13.5 pmra=0.263(0.373) pmdec=-7.070(0.330) G=18.124 BP=18.710 RP=17.038 175627.901 -171453.73 (2000.0) Gaia_EDR3_4144602552564272000 plx=0.202(0.187) dismod=13.5 pmra=0.851(0.177) pmdec=-6.670(0.121) G=18.119 BP=18.871 RP=17.093 was relatively variable both in ZTF and ATLAS. Nova containing a giant? (such as a symbiotic one)

1 0

[vsnet-newvar 9796] Gaia23atn
by Taichi Kato 20 Feb '23

20 Feb '23

Gaia23atn Gaia23atn AT2023cgz 2023-02-17 23:48:25 343.95057 46.56566 14.67 unknown 2023-02-19 16:26:35 Transient on very faint PanSTARRS source http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia23atn/ Not seen in outburst in the past ATLAS and ZTF data.

1 0

[vsnet-newvar 9795] ASASSN-23ax: new SU UMa-type dwarf nova
by Taichi Kato 20 Feb '23

20 Feb '23

ASASSN-23ax: new SU UMa-type dwarf nova Josch Hambsch has reported observations. Superhumps with a period of 0.0545(2) d (allowing aliases) were detected (0.2 mag).

1 0

[vsnet-newvar 9794] ASASSN-23af: oscillations during long rebrightening
by Taichi Kato 20 Feb '23

20 Feb '23

ASASSN-23af: oscillations during long rebrightening Josch Hambsch has reported further observations. At least three peaks (reaching 15 mag) have been detected during the long rebrightening.

1 0

[vsnet-newvar 9793] CSSJ091017.4-200812 superoutburst (AM CVn)
by Taichi Kato 19 Feb '23

19 Feb '23

CSSJ091017.4-200812 superoutburst (AM CVn) The last recorded one in 2019. No superhump observations yet. YYYYMMDD(UT) mag observer 20230209.9779 19.079o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230210.6977 <163C (Masayuki Moriyama) 20230214.9575 14.685o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230214.9629 14.692o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230214.9667 14.671o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230214.9790 14.696o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230216.1323 14.603c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230216.1350 14.597c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230216.1381 14.619c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230216.1613 14.617c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230217.2965 14.846zr (ZTF Alert DC mag (Masci+ 2019))

1 0

[vsnet-newvar 9792] Re: Yamamoto-san's object = CX137 = CXO GBSJ175553.2-281633 = OGLE-BLG-ELL-12042
by Taichi Kato 19 Feb '23

19 Feb '23

> My correct location data is below. > RA 17 55 53.29 > Dec -28 16 34.1 Sorry, I copied the location of CX137 by mistake.

1 0

[vsnet-newvar 9791] Yamamoto-san's object = CX137 = CXO GBSJ175553.2-281633 = OGLE-BLG-ELL-12042
by Taichi Kato 19 Feb '23

19 Feb '23

Yamamoto-san's object = CX137 = CXO GBSJ175553.2-281633 = OGLE-BLG-ELL-12042 Itoh-san's refined astrometry: RA 17 55 53.262 DEC -28 16 33.96 The location agrees with that of CX137. This is an outburst from a 0.4-d binary with prominent ellipsoidal variations. CX137: 175553.262 -281633.96 (2000.0) Gaia_EDR3_4062657359687091584 plx=1.130(0.049) dismod=9.7 pmra=1.164(0.052) pmdec=-6.889(0.035) G=16.223 BP=16.755 RP=15.373 Yamamoto-san reported that it had brightened further in the ASAS-SN data. https://asas-sn.osu.edu/sky-patrol/coordinate/b4aa63c1-fb92-40c0-96d4-2989b… Itoh-san obtained a short time-resolved photometric run (around 12.7 mag). This object may be eclipsing and further observations are recommended.

1 0

[vsnet-newvar 9790] Re: CX137 = CXO GBSJ175553.2-281633 = OGLE BLG-ELL-12042 outburst
by Taichi Kato 18 Feb '23

18 Feb '23

Re: CX137 = CXO GBSJ175553.2-281633 = OGLE BLG-ELL-12042 outburst Itoh-san provided astrometry: RA:17 55 53.13 DEC:-28 16 35.4 The location is a few arcseconds different from that of CX137. The outbursting object may not be CX137 and could be a different type of outbursting object (such as a nova). CX137: 175553.262 -281633.96 (2000.0) Gaia_EDR3_4062657359687091584 plx=1.130(0.049) dismod=9.7 pmra=1.164(0.052) pmdec=-6.889(0.035) G=16.223 BP=16.755 RP=15.373

1 0