README web version of /home/usg/OPS/MTS/readme_xml/readme_60944000

Principal Investigator Email Address

• cwolf@astro.ox.ac.uk

Estimated Total Execution Time (hours, including overheads)

• 0.5

General Description

• Ultra-cool White Dwarfs (UCWDs) are a class of unexplained objects, about
   which very little is known. UCWD SEDs deviate strongly from black bodies; they peak
   in the V-band and drop off ~10x in flux to the u-band or 1 micron. No spectral features
   have ever been observed. We propose to obtain the best-quality spectrum of LHS 1402,
   the coolest and second-brightest known UCWD, and furthermore in the Southern sky
   at -28 deg declination. It is presently unclear how subtle the atmospheric features
   of UCWDs might be, but we intend to push the limits using the VLT, including the
   previously unstudied NIR regime. We aim to see any atmospheric features of any plausible
   width, or slight local depressions in the continuum due to weak broadened features
   or binarity.
  
  We need the ADCs and the slit in the parallactic angle to avoid lambda-dependent
   slit losses. We expect that a 20 min exposure will give an S/N~30 in the B-band,
   >10 in the I-band, hopefully 5-10 in J-band, and possibly <1 in K-band. However,
   the SEDs of UCWDs in the NIR are plainly unknown.
  
  REMARK on FC: Due to the high proper motion, the object will have moved since the
   plates of the FC have been taken. However, my attached FC is a colour composite
   of an early DSS-1 image in blue and a later ESO R plate in red. The marked target
   is visible as two sources in different colour due to the proper motion. I have also
   drawn the approximate proper motion vector into the FC.

Waiver Requests

• No Waiver Request was submitted

Critical Observing Condition Constraints

• Just relatively low airmass (<1.3) to keep degrading effects (telluric
   absorption) on spectrum small

Time-Critical Aspects

• none

Special Execution Requirements

• ---(Empty)---

Special Calibration Information

• ---(Empty)---

ToO Information

• ---(Empty)---

ToO Activators List

• ---(Empty)---

Do all your OBs comply with the instrument-specific requirements listed
 on the instrument-specific Phase 2 web page ?

• YES

Do all your finding charts comply with both the general and instrument-specific
 Phase 2 Web Pages ?

• YES

If you submitted OBs for standard stars, did you specify the magnitude
 and spectral type of all standard stars in the OBs ?

• N/A

Have you specified the S/N ratio at given wavelength in the User Comments
 field of each OB?

• YES

Have you included OBs for any calibrations that you need but which are
 not part of the Calibration Plan ?

• N/A

If you are observing Moving Targets, have you attached suitable ephemeris
 files to your OBs?

• N/A

If you have preferences which OBs should be executed first, did you make
 use of the User Priority field in the OBs ?

• N/A

If this is a run that requires coordinated observations with other facilities,
 did you give proper instructions in the Time-Critical Aspects Section ?

• N/A