DRAFT
2021-08-18 13:15:03
Type: Object/s-Data/Analysis
Bibcode: 2021TNSAN.221....1F
Pan-STARRS follow-up of AT2021qvw: A rapidly evolving LBV outburst turning into an SN like event.
Authors: M. Fulton, S. J. Smartt, K. W. Smith (QUB), K. C. Chambers, M. Huber (IfA, Hawaii), S. Srivastav, D. R. Young, J. Gillanders, S. Sim (QUB), T. de Boer, J. Bulger, J. Fairlamb, C.-C. Lin, T. Lowe, E. Magnier, A. Schultz, R. J. Wainscoat, M. Willman (IfA), T.-W. Chen (Stockholm), D. E. Wright (University of Minnesota), C. Stubbs (Harvard), A. Rest (STScI)
Source Group: Pan-STARRS
Keywords: Supernova, Transient
Abstract:
We report the Pan-STARRS follow-up of the intrinsically faint transient AT2021qvw as an LBV-turning-supernova like event in the host galaxy CGCG 454-019, at a redshift of z = 0.025, or d = 111 Mpc (from NED). The transient initially faded quickly over a period of 10 days (to r~23), but has now brightened to r=19.4. This transient resembles a 2009ip-like explosion in its early phases; therefore, spectroscopic classification is strongly encouraged.

We are carrying out the "Pan-STARRS Search for Kilonovae", which is a focused search for intrinsically faint transients, or rapidly evolving transients in galaxies that are closer than 200 Mpc in the ongoing Pan-STARRS Near-Earth Object surveys (see Smartt et al. AstroNote 2019-48 for details). In normal survey mode, Pan-STARRS1 and Pan-STARRS2 telescopes take 4 x 45s exposures in w, i or z each night, reaching 5 sigma magnitudes of w<22, i<21 and z<20.5 in each frame (see Chambers et al. 2016, 1612.05560). The w-band filter is a broad g+r+i composite. 

We report the Pan-STARRS follow-up of the intrinsically faint transient AT2021qvw (Fulton et al. AstroNote 2021-179), which indicates that it may be an LBV eruption that is turning into a supernova like event in the host galaxy CGCG 454-019, at a redshift of z = 0.025, or d = 111 Mpc (from NED).

The transient was discovered on MJD 59386.55 (2021-06-21, 13:14:16 UT) at mag m_w = 21.40 +/- 0.16 (see Fulton et al. AstroNote 2021-179 for further details) and followed extensively over ten days. Decline rates of 0.32 +/- 0.07 mag/day, 0.15 +/- 0.03 mag/day, 0.17 +/- 0.04 mag/day and 0.13 +/- 0.04 mag/day were measured in the PS1 w, r, i and z bands respectively.

We revisited the transient's location on MJD 59437.41 (2021-08-11, 9:53:16 UTC), observing the transient had rebrightened. On MJD 59443.46 (2021-08-17, 11:01:38 UTC) we measured magnitudes of g = 19.59 +/- 0.04, r = 19.35 +/- 0.03 and i = 19.38 +/- 0.03, implying incline rates of >0.5 mag per day in each filter over three days. This transient may be a luminous LBV eruption, which rapidly declined and then undergone a supernova like explosion, similar to the events in SN2009ip (e.g. Mauerhan et al. 2013 MNRAS, 430, 18;  Pastorello et al. 2013, ApJ 767, 1). Spectroscopic classification and follow-up are strongly encouraged.

Operation of the Pan-STARRS1 and Pan-STARRS2 telescopes is primarily supported by the National Aeronautics and Space Administration under Grant No. NNX12AR65G and Grant No. NNX14AM74G issued through the SSO Near-Earth Object (NEO) Observations Program. The discoveries from the "Pan-STARRS Search for Kilonovae" program are a byproduct of the Pan-STARRS NEO survey observations. Data are processed at Queen's University Belfast enabled through the STFC grants ST/P000312/1 and ST/T000198/1. 

Show current TNS values
Catalog Name Reported RA Reported DEC Reported Obj-Type Reported Redshift Host Name Host Redshift Remarks TNS RA TNS DEC TNS Obj-Type TNS Redshift
TNS 2021qvw [PS21gqd] 23:16:38.285 +15:53:39.97 CGCG 454-019 0.025364 23:16:38.286 +15:53:40.01 SN II 0.025364
AstroNote Publication Timestamp Title Authors
2019-48 2019-07-20 17:37:13 Pan-STARRS Search for Kilonovae : discovery of an intrinsically faint transient in UGC 12798 (68 Mpc) S. J. Smartt, (Queen's University Belfast), K. C. Chambers, (IfA, University of Hawaii) K. W. Smith (QUB), M. Huber (IfA), S. Srivastav, O. McBrien, D. R. Young, J. Gillanders, D. O'Neil, P. Clark, S. Sim, (QUB), T. de Boer, J. Bulger, J. Fairlamb, C.-C. Lin, T. Lowe, E. Magnier, A. Schultz, R. J. Wainscoat, M. Willman (IfA), T.-W. Chen (MPE), D. E. Wright (University of Minnesota), C. Stubbs (Harvard), A. Rest (STScI)
2021-179 2021-06-25 14:10:20 Pan-STARRS Search for Kilonovae: discovery of a fast fading and intrinsically faint transient (AT2021qvw) in CGCG 454-019 (111 Mpc) M. Fulton, S. J. Smartt, K. W. Smith, D. R. Young, L. J. Shingles, S. Srivastav, (QUB), K. C. Chambers, M. Huber (IfA, Hawaii), M. Nicholl (Birmingham), J. Gillanders, S. Sim (QUB), T. de Boer, J. Bulger, J. Fairlamb, C.-C. Lin, T. Lowe, E. Magnier, A. Schultz, R. J. Wainscoat, M. Willman (IfA), T.-W. Chen (Stockholm), D. E. Wright (University of Minnesota), C. Stubbs (Harvard), A. Rest (STScI)

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