{
  "subject": "Refined Swift UVOT Analysis of SN 2008D (Transient in NGC 2770)",
  "editedOn": 1746219397743,
  "version": 2,
  "eventId": "SN 2008D",
  "bibcode": "2008GCN..7168....1I",
  "createdOn": 1200084398000,
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>",
  "circularId": 7168,
  "submitter": "Stefan Immler at NASA/GSFC  <immler@milkyway.gsfc.nasa.gov>",
  "email": "immler@milkyway.gsfc.nasa.gov",
  "format": "text/plain",
  "body": "S. Immler (NASA/UMCP/GSFC), A. Cucchiara (PSU),  D. Fox (PSU),\nA.M. Soderberg (Princeton U), E. Berger (Princeton U), K. Page (Leicester\nU), P. O'Brian (Leicester U), D. Burrows (PSU), and N. Gehrels (GSFC),\nreport on behalf of the Swift team:\n\nAn optical counterpart to the X-ray transient in NGC 2770, now SN 2008D\n(Atel 1353, 1355, GCN 7159-7167, CBET 1202), was marginally detected\nwith the Swift Ultraviolet/Optical Telescope (UVOT) in observations\nstarting 2008-01-09 13:32:53 UT. The following UVOT magnitudes were\nmeasured: b = 20.5�0.3 (412 s exposure time) and u = 20.2�0.4 (412 s).\nUpper limits were established for the other UVOT filters, v > 19.9 (412 s,\n3-sigma), uvw1 > 20.4, uvm2 > 20.3, and uvw2 > 20.8.\n\nThe following UVOT magnitudes were measured for observations\nstarting 2008-01-11 02:37:28 UT:  v = 18.5�0.2 (216 s exposure time),\nb = 18.9�0.1 (353 s), u = 18.6�0.1 (664 s), uvw1 = 19.8�0.2 (1707),\nuvm2 > 19.8 (3-sigma UL, 571 s), uvm2 = 20.1�0.3 (864 s), and uvm2 >\n20.4 (864 s).\n\nWe note that no optical/ultraviolet source was detected at the location of\nthe transient during routine observations of SN 2007uy on 2008-01-06\n00:31:23 UT, down to the following 3-sigma upper limits: v > 20.2 (808 s\nexposure time), b > 21.1 (808 s), u > 20.7 (808 s), uvw1 > 20.8 (1619 s),\nuvm2 > 20.7 (2187 s), uvw2 > 21.2 (3234 s).\n\nThese magnitudes are on the UVOT photometric system (see Poole et al.,\n2007, MNRAS, 383, 627) which in the optical is close to the Johnson UBV\nsystem. They have not been corrected for Galactic extinction of E(B-V) =\n0.023 mag (Schlegel et al. 1998, ApJ 500, 525). The UVOT photometry\nand colors are similar to the early UVOT phase of SN 2006aj/GRB060218\n(e.g., Campana et al. 2006, Nature 442, 1008) and consistent with an\nemerging supernova, although other possibilities cannot be ruled out."
}