Night report 2014-02-22
Observers: Morgan Fraser, Heather Campbell
Support team: Nadia Blagorodnova, Nic Walton
TAT: Nancy Elias-Rosa, Annalisa De Cia
All followup observations for the subrun were completed, with the exception of SN 2012ec (as we did not have photometric conditions), the last set of 12x200s imaging for LSQ12dlf (as the seeing was too poor), and the JHK imaging for SN 2013fc (as we did not have time for an instrument switch). We revisited two of the "blue featureless" classifications from earlier in the run.
Moon: 44% illumination, UT 04.30 onwards
Humidity 40%, wind ~5 miles per hour, non-photometric
Varying and poor seeing (~1.5") for the first ~2 hr of the night, subsequently stabilized at 1" for rest of night.
1" or better throughout night (from DIMM and measured off images)
23.31 Start of twilight
TO started to perform image analysis, but aborted this as the seeing was ~1.5"
2x1800s Gr#11 followup. Note that as LSQ12dlf was not observed due to poor seeing, we could spend longer on this target).
00.48 End of twilight
01.30 Seeing improved, TO performed image analysis
BV photometry (taken in dark time before moon is up)
4x1800s Gr#11 (target reacquired after first 2x1800s exposure).
04.55 LTT3864 spectrophotometric standard
Repeat of previous ambiguous classification, 1800s Gr#13. Narrow absorption at 5334 Ang in both this and in the previous classification spectrum from Feb 20. Also possible broad feature at ~4350 Ang in both spectra.
600s Gr#13 classification - young Type II SN, best matches at z=0.03
900s Gr#13 classification. Could not measure offset for transient from nucleus of host galaxy, so we used a 1.5' slit centred on core of galaxy. Extracting both galaxy and transient, we get a match to a Ia at z=0.04, and with an age between ~ -1 and +1 week
600s Gr#13, Type Ia SN at z=0.009, at one to two months post max.
LSQ lightcurve shows a fast (5d) rise and similar speed decline. Decided to take another spectrum, as previous classification was ambiguous (blue and featureless). 1800s Gr#13 appears unchanged from before. Obvious apparent host galaxy in LSQ images.
3x1800s Gr#11 followup
09.06 Start of twilight
600s Gr#13 classification. Young Type II SN in NGC 3905. Blue continuum with broad Halpha and Hbeta in emission. Also apparent narrow emission line at 4657 (observed frame). Not sure what this could be (if real), it's the wrong wavelength for HeII.
09.29 EG274 - spectrophotometric standard
09.55 BR skyflats
10.21 End of twilight