README web version of /home/usg/OPS/MTS/readme_xml/readme_75063700

Principal Investigator Email Address

```
claire.martin@oamp.fr
```

Estimated Total Execution Time (hours, including overheads)

```
03:00:00
```

General Description

We propose to observe at high spectral resolution a sample of Herbig stars
 for which we have already measured the amount of circumstellar molecular hydrogen
 from FUSE data. The analysis of interstellar and/or circumstellar lines at optical
 wavelengths, especially CH and CH+ lines, combined to our H2 data, will allow us
 to explain the chemical mechanisms of formation/destruction and excitation of the
 different molecules in the circumstellar environment of HAeBes.

We absolutely need the maximum spectral resolution (~80,000, slit width=0.4) to
 separate the different gaseous components along the line of sight. High S/N ratio
 (S/N>150) is required to detect the very weak CS lines one would expect to observe
 in the CS environment of our target stars. Indeed, although CH absorption lines
 are generally broad, lines of CH+ are very weaker and are the most important lines
 in our study to constrain the excitation conditions of the CS gas.

Waiver Requests

```
No Waiver Request was submitted
```

Critical Observing Condition Constraints

All the OBs need at least:
Sky transparency: variable, thin cirrus
Seeing less than 1.0
airmass less than 1.6
no constraints on the lunar phase

Time-Critical Aspects

no time-critical aspects associated with this run.

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

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

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 ?

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

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N/A
```

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

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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 ?

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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 ?

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N/A
```

If you need secondary guiding, are there suitable objects within 30 arcsec from your target ?

```
N/A
```

Last creation of page: Tue Oct 6 15:40:08 2009
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