AstroNote 2020-88

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DRAFT
2020-04-21 22:40:37
Type: Object/s-Discovery/Classification
Pan-STARRS Search for Kilonovae: discovery of three intrinsically faint transients within 200 Mpc
Authors: K. W. Smith, S. J. Smartt (QUB), K. C. Chambers, M. Huber (IfA, Hawaii), S. Srivastav, O. McBrien, D. R. Young, J. Gillanders, D. O'Neill, 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 (Stockholm), D. E. Wright (University of Minnesota), C. Stubbs (Harvard), A. Rest (STScI)
Source Group: Pan-STARRS1
Abstract:
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 which are closer than 200 Mpc in the ongoing Pan-STARRS Near Earth Object surveys (see Smartt et al. AstroNote 2019-48 for details).  PS20cfp (AT2020hud) is in host galaxy KUG 1218+190, at a redshift of z = 0.045, or d = 193 Mpc (from NED). Its discovery magnitude (MJD = 58957.44) is w = 19.75 +/- 0.03, and hence an absolute magnitude of M_w = -16.76 +/- 0.03. PS20cfs (AT2020huf) is in host galaxy IC 0827, at a redshift of z = 0.022, or d = 98 Mpc (from NED). Its discovery magnitude (MJD = 58957.44) is w = 21.25 +/- 0.12, and hence an absolute magnitude of M_w = -13.79 +/- 0.12. PS20ccs (AT2020hug) is in host galaxy SDSS J122102.51+190054.3, at a redshift of z = 0.045, or d = 191 Mpc (from NED). Its discovery magnitude (MJD = 58957.44) is w = 20.03 +/- 0.04, and hence an absolute magnitude of M_w = -16.46 +/- 0.04.

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 which 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-STARRS takes 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). 

PS20cfp (AT2020hud) is in host galaxy KUG 1218+190, at a redshift of z = 0.045 or d = 193 Mpc (from NED).  The transient was discovered at MJD 58957.44 == 2020-04-18.44, at m_w = 19.75 +/- 0.03. It is offset from the host by 6.2" S, 7.7" E (a projected 8.7 kpc radius from the galaxy centre). At this distance the absolute magnitude is M_w = -16.76 (assuming m-M = 36.42 and foreground extinction of A_r = 0.09).

PS20cfs (AT2020huf) is in host galaxy IC 0827, at a redshift of z = 0.022 or d = 98 Mpc (from NED).  The transient was discovered at MJD 58957.44 == 2020-04-18.44, at m_w = 21.25 +/- 0.12. It is offset from the host by 4.78" S, 15.44" W (a projected 8.1 kpc radius from the galaxy centre). At this distance the absolute magnitude is M_w = -13.79 (assuming m-M = 34.95 and foreground extinction of A_r = 0.09).

PS20ccs (AT2020hug) is in host galaxy SDSS J122102.51+190054.3, at a redshift of z = 0.045 or d = 191 Mpc (from NED).  The transient was discovered at MJD 58957.44 == 2020-04-18.44, at m_w = 20.03 +/- 0.04. It is offset from the host by 3.0" N, 4.0" W (a projected 4.4 kpc radius from the galaxy centre). At this distance the absolute magnitude is M_w = -16.46 (assuming m-M = 36.40 and foreground extinction of A_r = 0.09).

Spectroscopic classification is encouraged.

 We will release AstroNotes for all these candidates and encourage spectroscopic classification or photometric follow-up.  Finders are attached. 

These discoveries are a byproduct of the Pan-STARRS NEO survey observations supported by the NASA Grants, including No. NNX14AM74G issued through the SSO Near Earth Object Observations Program.

 

Show current TNS values
CatalogNameReported RAReported DECReported Obj-TypeReported RedshiftHost NameHost RedshiftRemarksTNS RATNS DECTNS Obj-TypeTNS Redshift
TNS2020hud [PS20cfp]12:21:24.613+18:44:27.520.04512:21:24.613+18:44:27.52
TNS2020huf [PS20cfs]12:51:53.990+16:16:53.450.02212:51:53.989+16:16:53.57
TNS2020hug [PS20ccs]12:21:02.235+19:00:57.320.04512:21:02.230+19:00:57.24