RA/DEC (2000)
12:42:04.025 +32:32:07.88
190.516772235 +32.5355208587
Type
LRN
Redshift
0.002021
Discovery ReportClassification Report
Related AstroNotes: 2021-33
Reporting Group
ATLAS
Discovering Data Source
ATLAS
Discovery Date
2021-01-29 13:24:57.600
TNS AT
Y
Public
Y
Discovery Mag
18.12
Filter
orange-ATLAS
Reporter/s
J. Tonry, L. Denneau, A. Heinze, H. Weiland (IfA, University of Hawaii), B. Stalder (LSST), A. Rest (STScI), C. Stubbs (Harvard University), K. W. Smith, S. J. Smartt, D. R. Young, S. Srivastav, O. McBrien, M. Fulton, J. Gillanders (Queen's University Belfast), T.-W. Chen (MPE), D. E. Wright (University of Minnesota), J. Anderson (ESO)
NEDSIMBADDECaLSPanSTARRS-1SkyMapperVizieRWISEDSSADS

Spectra

 ▌AT_2021biy - 2020-01-31 02:52:48 NOT / ALFOSC (Padova-Asiago)z=
▌Show H at z=vexp= km/s
▌Show He at z=vexp= km/s
▌Show He II at z=vexp= km/s
▌Show C II at z=vexp= km/s
▌Show C III at z=vexp= km/s
▌Show C IV at z=vexp= km/s
▌Show N II at z=vexp= km/s
▌Show N III at z=vexp= km/s
▌Show N IV at z=vexp= km/s
▌Show N V at z=vexp= km/s
▌Show O at z=vexp= km/s
▌Show [O I] at z=vexp= km/s
▌Show O II at z=vexp= km/s
▌Show [O II] at z=vexp= km/s
▌Show [O III] at z=vexp= km/s
▌Show O V at z=vexp= km/s
▌Show O VI at z=vexp= km/s
▌Show Na at z=vexp= km/s
▌Show Mg at z=vexp= km/s
▌Show Mg II at z=vexp= km/s
▌Show Si II at z=vexp= km/s
▌Show S II at z=vexp= km/s
▌Show Ca II at z=vexp= km/s
▌Show [Ca II] at z=vexp= km/s
▌Show Fe II at z=vexp= km/s
▌Show Fe III at z=vexp= km/s
▌Show Å at z=vexp= km/s
▌Show Å at z=vexp= km/s
▌Show Å at z=vexp= km/s
▌Show Å at z=vexp= km/s
▌Show Tellurics 
▌Show Galaxy lines at z=
▌Show WR-WN at z=vexp= km/s
▌Show WR-WC/O at z=vexp= km/s
   Binning factor: (rounded to nearest integer >1)
Mouse hovers at WL: 0 (rest),0 (observed)

Light curves

 ▌PS2_GPC2_i
 ▌ATLAS-MLO_ATLAS-01_orange
 ▌ATLAS-HKO_ATLAS-02_orange
 ▌PS1_GPC1_i
   
Pointer position (MJD, Mag, Abs.Mag): (0.00, 0.00, 0.00)
Spectra
 ID Obs-date (UT) Tel / Inst Exp-Time Observer/s Reducer/s Group Spectrum ascii file Spectrum fits file Spec. Type Assoc. Groups End prop. period Remarks
8818 2020-01-31 02:52:48 NOT / ALFOSC Y.-Z. Cai A. Pastorello Padova-Asiago tns_2021biy_2020-01-31.12_NOT_ALFOSC_Padova-Asiago.txt Object 2021-08-06
Light Curves
Filter Tel / Inst Obs-date range JD Range Photometry
i-P1 PS2_GPC2 2021-03-31 11:58:34 - 2021-03-31 11:58:34 2459304.999 - 2459304.999 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
202598 2021-03-31 11:58:34 2459304.999 17.4 0.03 20.7 ABMag i-P1 PS2_GPC2 45 Robot
orange-ATLAS ATLAS-MLO_ATLAS-01 2021-01-24 13:17:46 - 2021-01-24 13:17:46 2459239.054 - 2459239.054 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
188946 2021-01-24 13:17:46 2459239.054 19.52 ABMag orange-ATLAS ATLAS-MLO_ATLAS-01 30 Robot [Last non detection]
orange-ATLAS ATLAS-HKO_ATLAS-02 2021-01-29 13:24:58 - 2021-01-29 13:24:58 2459244.059 - 2459244.059 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
188947 2021-01-29 13:24:58 2459244.059 18.12 0.14 18.65 ABMag orange-ATLAS ATLAS-HKO_ATLAS-02 30 Robot
i-P1 PS1_GPC1 2021-02-10 12:46:05 - 2021-02-10 12:46:05 2459256.032 - 2459256.032 1
Photometry
ID Obs-date JD Mag. / Flux Err Lim. Mag./Flux Units Filter Tel / Inst Exp-time Observer/s Remarks
191997 2021-02-10 12:46:05 2459256.032 16.33 0.02 20.7 ABMag i-P1 PS1_GPC1 27 Robot
AT Reports
ID Time received (UT) Sender Reporter/s Reporting group Disc. Data Source RA DEC Discovery date (UT) Discovery Mag. Filter Related files AT Type Host name Internal name Assoc. Groups End prop. period Remarks ADS Bibcode Unreal Auto classification
104953 2021-04-03 23:32:23 PS2_Bot1 K. C. Chambers,T. de Boer,J. Bulger et al. Pan-STARRS Pan-STARRS 12:42:04.025 +32:32:07.88 2021-03-31 11:58:33.600 17.4 i-P1 PSN PS21aaa Pan-STARRS N
99186 2021-02-11 03:15:53 YSE_Bot1 D. O. Jones (UC Santa Cruz),K. D. French (Carnegie,Illinois) et al. YSE Pan-STARRS 12:42:04.024 +32:32:07.92 2021-02-10 12:46:04.800 16.33 i-P1 PSN PS21aaa Pan-STARRS N
97951 2021-01-29 16:41:26 ATLAS_Bot1 J. Tonry,L. Denneau,A. Heinze et al. ATLAS ATLAS 12:42:04.020 +32:32:07.58 2021-01-29 13:24:57.600 18.12 orange-ATLAS PSN ATLAS21dfy ATLAS 2021TNSTR.273....1T N
Classification Reports
ID Time received (UT) Sender Classifier/s Group Classification Redshift Spectra Related files Assoc. Groups End prop. period Remarks ADS Bibcode
8808 2021-02-06 13:59:03 Andrea Reguitti Y.-Z. Cai Padova-Asiago LRN 0.002021 1 Add Padova-Asiago The spectrum shows a relatively blue continuum dominated by prominent Balmer lines in emission, with an unresolved narrow component superposed on a broader base (with FWHM ~2500 km/s). Narrow lines of Fe II, Ca II and O I are also identified. A narrow absorption of Na I is visible at the redshift of the host galaxy, with an equivalent width (EW) of 1.6 A, suggesting additional host galaxy extinction. Adopting the correlation between EW of Na I and color excess E(B-V) of Turatto et al. 2003, we obtain E(B-V) = 0.25 mag. The object has also been targeted in photometry on January 30.05 UT at the 62/92-cm Schmidt telescope of Asiago, at a magnitude V=18.0 (and B-V = 0.3 mag). Adopting for NGC 4631 a TRGB distance of 7.52 Mpc (Monachesi et al. 2016, MNRAS, 457, 1419), we infer for the transient an absolute magnitude M_V ~-12.1. The overall properties are consistent with those of a luminous red nova (LRN) soon after the early blue maximum (Pastorello et al. 2019, A&A, 630, A75), although an LBV-like outburst cannot be ruled out. [Ca II] lines are not clearly detected in the spectrum, hence the classification as an Intermediate-Luminosity Red Transient is less likely (Pastorello & Fraser 2019, Nature Astron. 3, 676). Due to its high luminosity (even without accounting for the host galaxy extinction), we rule out that AT 2021biy is a classical nova. The redshift of the host galaxy is from De Vaucouleurs et al. 1991, RC3, v. 3.9. 2021TNSCR.369....1C
Spectra
ID Obs-date (UT) Tel / Inst Exp-Time Observer/s Reducer/s Group Spectrum ascii file Spectrum fits file Spec. Type Assoc. Groups End prop. period Remarks
8818 2020-01-31 02:52:48 NOT / ALFOSC Y.-Z. Cai A. Pastorello Padova-Asiago tns_2021biy_2020-01-31.12_NOT_ALFOSC_Padova-Asiago.txt Object 2021-08-06

Comments

TNS
System

Sat, 04/03/2021 - 23:30

Object coordinates updated

Object coordinates updated according to AT-report 104953 of Group Pan-STARRS1
Previous RA, DEC: 12:42:04.024, +32:32:07.92 (190.516767075, +32.5355332655)
Updated RA, DEC: 12:42:04.025, +32:32:07.88 (190.516772235, 32.5355208587)

TNS
System

Thu, 02/11/2021 - 02:30

Object coordinates updated

Object coordinates updated according to AT-report 99186 of Group Pan-STARRS1
Previous RA, DEC: 12:42:04.020, +32:32:07.58 (190.51675, +32.53544)
Updated RA, DEC: 12:42:04.024, +32:32:07.92 (190.516767075, 32.5355332655)