TNS Classification Report No. 10382 [ 2021TNSCR2741....1N ]
Date Received (UTC): 2021-08-09 17:44:14 Sender: Megan Newsome
Group: Global SN Project
Megan Newsome (UCSB/Las Cumbres), Iair Arcavi (TAU), Marco C Lam (TAU), Yael Dgany (TAU), Jamison Burke (LCO/UCSB), Daichi Hiramatsu (LCO/UCSB), D. Andrew Howell (LCO/UCSB), Curtis McCully (LCO/UCSB), Estefania Padilla Gonzalez (LCO/UCSB), Craig Pellegrino (LCO/UCSB) report/s a classification of object: AT 2018bby
Type: Varstar
Remarks: We report a candidate dwarf nova/polar/intermediate nova system (under the transient designations: AT2018bby, ZTF20aammhxq, and ATLAS18nuj) that had outbursts in three occasions with an amplitude of ~6mag. Low-state durations are ~600days. It was reported as a candidate hot white dwarf in Bianchi et al. (2011) with Galex FUV=22.56 and NUV=22.95, and SDSS u=22.53, g=22.98, r=22.88, i=21.85, and z=22.83. The first outburst was reported as a supernova candidate ATLAS18nuj, reaching a maximum brightness of o=17.33 at UT 2018-04-26 11:39:50. The second and third outbursts were observed by ZTF reaching r=16.955 at UT 2020-02-09 12:08:54 and r=17.391 at UT 2021-08-04 05:29:02 at maximum. The spectrum shows weak H-alpha and some He emission lines. From H-beta to H-zeta, there are either emission lines on top of the absorption profiles, or Zeeman splitting features, suggesting a polar or intermediate polar system.
The following Classification spectrum was provided:
Obsdate: 2021-08-07 06:22:38
Instrument: FLOYDS-N
Telescope: Faulkes Telescope North
Details of the object and its spectra can be viewed here: https://www.wis-tns.org/object/2018bby
Date Received (UTC): 2021-08-09 17:44:14 Sender: Megan Newsome
Group: Global SN Project
Megan Newsome (UCSB/Las Cumbres), Iair Arcavi (TAU), Marco C Lam (TAU), Yael Dgany (TAU), Jamison Burke (LCO/UCSB), Daichi Hiramatsu (LCO/UCSB), D. Andrew Howell (LCO/UCSB), Curtis McCully (LCO/UCSB), Estefania Padilla Gonzalez (LCO/UCSB), Craig Pellegrino (LCO/UCSB) report/s a classification of object: AT 2018bby
Type: Varstar
Remarks: We report a candidate dwarf nova/polar/intermediate nova system (under the transient designations: AT2018bby, ZTF20aammhxq, and ATLAS18nuj) that had outbursts in three occasions with an amplitude of ~6mag. Low-state durations are ~600days. It was reported as a candidate hot white dwarf in Bianchi et al. (2011) with Galex FUV=22.56 and NUV=22.95, and SDSS u=22.53, g=22.98, r=22.88, i=21.85, and z=22.83. The first outburst was reported as a supernova candidate ATLAS18nuj, reaching a maximum brightness of o=17.33 at UT 2018-04-26 11:39:50. The second and third outbursts were observed by ZTF reaching r=16.955 at UT 2020-02-09 12:08:54 and r=17.391 at UT 2021-08-04 05:29:02 at maximum. The spectrum shows weak H-alpha and some He emission lines. From H-beta to H-zeta, there are either emission lines on top of the absorption profiles, or Zeeman splitting features, suggesting a polar or intermediate polar system.
The following Classification spectrum was provided:
Obsdate: 2021-08-07 06:22:38
Instrument: FLOYDS-N
Telescope: Faulkes Telescope North
Details of the object and its spectra can be viewed here: https://www.wis-tns.org/object/2018bby