Night Report 2016-09-05

Observing: David Bersier, Lawrence Short

Support Team: Stephen Smartt

TAT: Joe Lyman, Kate Maguire

Weather conditions

Start of night: few clouds on horizon, seeing ~1.8"

Middle of night: Clear, seeing ~1.4"

End of night:

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Calibrations

Daytime: EFOSC bias, spec arcs and flats

Evening: UV flats

Morning: -

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All observations with EFOSC

23:38 SN2016eiy (follow-up) g11+g16

00:15 Pointing restriction in place

00:34 AT2016cvk (follow-up) gr11+gr16

01:33 SN2016egz (follow-up) gr13 slit=1" poor S/N

02:15 redid SN2016egz (follow-up) gr13 slit=1.5"

02:55 ASASSN-15oz (follow-up) gr13 slit=1.5" (wrong object?)

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04:45 Hand over to other observer

Notes from reductions (SJS) :

SN2016eiy - good S/N

AT2016cvk - good S/N

SN2016egz - S/N~20-25 in the continuum. The broad and strong lines are visible, certainly usable spectrum. But if high S/N needed for this bright target, then should redo.

ASASSN-15oz - objects are usually acquired at pixel X=550 (in the raw frame, or X=450 in the pipeline reduced and trimmed frame if you are looking at that). But there is no object at this X position in the first frame EFOSC.2016-09-06T02:55:50.826.fits.

There is weak extended flux at X=576 in the second frame, EFOSC.2016-09-06T03:51:17.420.fits, but again it's not at the normal acquisition position.

I took the acquisition images and calibrated them with PESSTOEFOSCPHOT.

Identification of the source with the shallow finder and the deeper 60s V-band EFOSC2 image is not easy ! There is huge mismatch between the depths of the finders, so I'm not surprised you found this difficult to acquire. But ASASSN-15oz is visible in the 60s finder and marked on the new finder below. You can get the calibrated FITS file below too.

You can redo this object tonight. I extracted some of the sources nearby the X=550 position in the frame, but I don't think any of them are

ASASSN-15oz. They are not sent to WISeREP. Also, the updated coords are as follows (different by about 1.5 arcsec from the ASSASN coords in the marshall)

19:19:33.56 -33:46.01.3

Tip for acquisition - take the 60s V-band image and run it through PESSTOEFOSCPHOT for instant astrometric calibration.

Load it up into ds9 (Select Zoom -> Align ; Edit -> Region. Double click on image and enter in the coords. As long as you have a shape like Circle selected under Region, then your circle will pop up at the object position). The astrometric calibration is usually excellent, so this is pretty much foolproof for target identification and acquisition.