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Night Report 2014-09-01

 Observers: Leonardo Tartaglia, Nancy Elias-Rosa
 Support: Enrico Cappellaro
 TAT on duty: Maria Teresa Botticella, Andrea Pastorello

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 WEATHER CONDITIONS:
 start: wind 13.0 m/s; temp. 8.7 C; humid. 29.9 % - Overcast.
 middle: wind 16.9 m/s; temp. 9.6 C; humid. 27.0 % - Cloudy.
 end: wind 16.1 m/s; temp. 10.4 C; humid. 24.1 % - Overcast.

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 INSTRUMENT: EFOSC2

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 CALIBRATIONS

 Afternoon:
 -- EFOSC2 bias, dome spec flats, arcs (impossible to do evening skyflats)

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 Not observations tonight due to the bad weather.





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Instructions for deep spectra of SN2013hx
The target is R=21.7, from imaging taken on 2014-08-25. It should be in the nebular phase, and dominated by emission lines. We expect to see [O I], [Ca II] and possibly H-alpha. But it is faint and at z=0.163, these lines are shifted into the dense night sky emission line region. We will attempt deep spectra, with 2D image subtraction. This just requires the object to be shifted, in X, along the slit in separate exposures. P2PP does not allow nodding along the slit for EFOSC2, so we need to do it manually. 

1800s at V=20.5 gave spectrum with reasonable S/N for LSQ14an, enough to detect the SN emission features. In the sky limited regime, we need 6 times longer to achieve comparable S/N. Hence 3hr total exposure required.  Always observe at PA. 

  1. 2700s with Gr13, standard OB (Spec_Very_faint_sources_g13_sl1.obx). This has "X Pixel Coordinate = 1100"
  2. 2700s (same OB) but set "X Pixel Coordinate  = 1260"  in ESO_img_acq_MovetoSlit (i.e. shift the spectrum in X direction by 80 binned pixels)
  3. 2700s (same OB) but set "X Pixel Coordinate  = 1260"  in ESO_img_acq_MovetoSlit (i.e. shift the spectrum in X direction by 80 binned pixels)
  4. 2700s with Gr13, standard OB (Spec_Very_faint_sources_g13_sl1.obx).  This has "X Pixel Coordinate = 1100"
  5. Do spectrophotometric standard immediately before or after this sequence - standard OBs
This will allow us to do 1-2 and 3-4 to give 2D sky subtracted images. This works well for other instruments. We haven't yet tried in PESSTO, but fairly sure it will work well. 

Only do if sky conditions are clear, seeing is <= 1.1", and dark sky conditions  If there is NO signal after the first 2700sec, then stop and abandon. You should see a faint trace in the 2700s individual exposures. 
Finder is linked on the wiki finder page.

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