README web version of /home/usg/OPS/MTS/readme_xml/readme_75070200

Principal Investigator Email Address

• sana@astro.ulg.ac.be

Estimated Total Execution Time (hours, including overheads)

• 7 hours

General Description

• We propose to acquire follow-up high S/N (>250) FEROS spectra of two
   bright (V=5.4-6.5) early type SB2 binaries. The aim is to constrain the period and
   derived the orbital parameters. To do so, we need to reach a sufficiant phase coverage.
   One of the critical points of this program is that the two periods are still ill
   constrained. 
  HD152234 (V=5.2) has a probable period of 126 days, but aliases at 55 and 27 days
   are possible alternative.
  HD152233 has a period larger than a few tens of days. Probable periods are 42 and
   260 days. 
  
  We thus require about 25 spectra spread over the entire P75. These should typically
   be separated by 6 days in order to probe the different probable periods. No scientific
   gain could be reached if the time separation between two obtained spectra is too
   small. The absolute minimal separation is 4 days (see more details in the  Time-Critical
   Aspects)
  
  The S/N is another crucial aspect as the brightness ratio between the binary component
   is larger than 10. S/N > 250 is thus critical to unambiguously disentangle the
   component spectrum.
  A re-evaluation of the schedule at mid-course would allow to optimize the allocated
   observing time (see Time Critical Aspects)

Waiver Requests

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Critical Observing Condition Constraints

• Sources are bright, program can be performed in about all seeing and coverage
   conditions.
  S/N >250 is a critical aspect. 
  Targets can be observed during twillight .
  Exposure times computed for thin cirrus coverage and seeing below 2 or 3". If the
   program is adopted as a backup program in the case of bad weather conditions (thick
   cirrus, awfull seeing, large airmass) which prevent other observations, please increase
   the exposure time accordingly. Summing up several successive exposures to achieve
   the requested S/N is also an alternative. 
  In any case, whatever the observing conditions, we will get science from our spectra
   if the requested S/N > 250 is reached.

Time-Critical Aspects

• Because of the target periods (see General Description), we required about
   22 follow-up spectra spread over the entire P75. These should be typically separated
   by 6 days in order to probe the different probable periods. No scientific gain is
   reached if the time separation between two obtained spectra is too small. The absolute
   minimal separation is 4 days. 
  According to the Service Mode allocated time on FEROS, we propose the following
   schedule for our observations (+-2nights):
  Apr17, Apr26, 
  May 1, May 6, May 11, May 15, May 28, 
  Jun 2, Jun8, Jun 14, Jun 26
  Jul 1, Jul 7, Jul 13,
  Aug 14, Aug 20, Aug 26
  Sept 1, Sept 8, sept 14
  Sept 25, Sept 30
  (to be performed untill the 22 allowed spectrum have been acquired)
  However, any other schedule yielding 22 spectra of each target spread over P75 and
   separated from the previous obtained spectra by typically 6 days is acceptable.
   
  
  Because of the still uncertain period, it would be particularly relevant to carry
   out an re-evaluation of the proposed schedule at mid-course in P75, especially to
   optimize the last SM large allocated period (Aug14-Sept15) according to the new
   contraints on the period that will be derived from the first set of observations.
   For this reason it would be of the greatest interest if we could get an acces to
   the data that will be obtained prior to Jul 14.

Special Execution Requirements

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Special Calibration Information

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ToO Information

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ToO Activators List

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Is this a Pre-imaging run ?

• false

Pre-imaging Requirements

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Source(s) of Pre-imaging

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Pre-imaging sources not listed above

• ---(Empty)---

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

• YES

If this is a pre-imaging run, did you select PRE-IMAGING for the Observing
 Category for each Observing Template ?

• N/A

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 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

Did you set 'New Preset' flag in all acquisition templates to 'True'?

• YES

If you use any lamp, did you check that it should never be left on at
 the end of any OB?

• N/A