README web version of /home/usg/OPS/MTS/readme_xml/readme_82045000

Principal Investigator Email Address

• Eric.Stempels@st-andrews.ac.uk

Estimated Total Execution Time (hours, including overheads)

• 4 hrs

General Description

• This observing run aims to obtain two spectra of GY 241, a very young
   source that is deeply embedded in the rho Oph star forming cluster. These spectra
   will reveal whether or not GY 241 shows radial velocity variations. If it shows
   radial velocity variations, the system is most likely a binary system.
  
  The period of the system (from photometry) is 2.95 days. We therefore request two
   observations on two different nights, preferrably on consecutive nights (see Time-Critical
   Aspects).
  
  Since the source is very red and very faint (J>18, H=15.8 and K=13.18), it will
   only be observable with CRIRES in the K-band. This is close to the detection limit
   of CRIRES. There are no other sources within 58", which will make it necessary to
   guide on the target itself. The source is also too faint in R for using the AO system.
  
  In connection with each observations, we request a ThAr calibration (included in
   the OB) and a telluric standard star (see Special Calibration Information).

Waiver Requests

• Approved waiver : 382.C-0450A.01
  
  - Exposure time > 1hr
  - Slit width > 0.4 arcsec

Critical Observing Condition Constraints

• Seeing < 0.8", Sky CLR. Moon > 30 degrees.
  
  The main target is very faint for CRIRES (H=15.8 and K=13.18).
  
  Please do not observe at a moon distance of less than 30 degrees (recommended value
   from CRIRES manual).

Time-Critical Aspects

• The object is only accessible at the end of period 82 (February &
   March). The main target OB and telluric standard take about 2 hrs to execute. The
   observations should therefore be started at least 2 hours before the end of the
   night.
  
  The orbital period of the system (from photometry) is 2.95 days. We need two observations
   at different orbital phases. Because the spectrum of the source might change over
   time, we would like to minimize the time between observations.
  
  We would therefore prefer observations on two consecutive nights. The exact timing
   of the target within a night is not critical.
  
  The expected orbital period is almost exactly 3 days. In order to obtain observations
   at different phases, the second observations should not be taken on a night that
   is a multiple of 3 nights after the earlier observation - 3, 6, 9, 12 etc. nights
   after the first observation (night 0).

Special Execution Requirements

• N/A

Special Calibration Information

• We request an attached wavelength calibration (ThAr) with every observation
   of the target. This has already been included in the OB.
  
  We also request a telluric standard to be observed after each observation of the
   main target. Our selected telluric standard has a declination that is very similar
   to that of the target, and an RA that is about 1hr later. The telluric standard
   star will then be located approximately in the same sky position as the main target.
  
  We expect a SNR per pixel of about 275 for our telluric standard (@ 2200nm; chose
   target SpTyp=B2IV, range: B1 - B4.)
  
  Default daytime calibrations will be sufficient.

ToO Information

• N/A

ToO Activators List

• N/A

Do the README file and the instrument comments of the telluric stars
 OBs include the required S/N/pixel of the spectrum of the telluric star, its spectral
 type and allowed spectral range?

• YES

Do any OBs include wavelength or flatfield calibrations?

• YES

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

• N/A

If the slit viewer guide star is different from the target, are the RA
 and DEC offsets accurate to within 0.05 arcsec and do they take into account the
 relative proper motion between the two objects?

• N/A

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

• N/A