Searching for Balmer Lines in Galactic RSGs

DIS Manual

Use the 0.9" slit and the high dispersion B1200 grating centered at 4280A. This gives me 3660A to 4900A (1240A total range). If I have more time at the very end maybe put in the B400 grating and just re-observe everything. Shorter exposure times and would give me some coverage of TiO bands.

Sunrise is at 5:56. Astronomical twilight ends at 4:14. Civil twilight ends at 5:27.

Big Table containing:

Exposure Times

If I assume the exposure times in the table (calculated using B magnitudes and the exposure time calculator) and then assume a 5 minute overhead, the 68 targets can be observed in 17 hours. If I multiply the exposure times by 5, it takes 63 hours. If I multiply by 10, it takes 121 hours.

If I take out the non-HL targets (9 of them ... mostly really faint), then given the criteria above I get 5.5 hours, 8 hours and 11 hours.

Calibrations and stuff

Arcs - He and Ar are good in the UV / blue. According to the manual section 4.2, the exposure time should be somewhere between 60 and 120s. I only need a few of these in the afternoon since I'm not doing radial velocities.

Flats - I want the S/N in the blue to be around 500. This will require a lot of flats. The maximum exposure is around 960s so every afternoon take maybe three or four 600s flats.

Standards - There is already a standards catalog here.

Parallactic Angle - calculate using sky calc. Input file with numbers. From website: "Again, remember that the commanded position angle needs to be set at 90 degrees from the desired parallactic angle!"

Finding Charts

Finding Chart website

Slitviewer camera is 2.7' on a side

Airmass calculator

SkyCalc Out

User Catalog

Observing Tricks

> implot comp to see if saturating
> implot flat to see if saturating
> implot object
       > type "c" in middle to check if saturating
       > peak counts x gain (1.68)
       > sqrt (peak counts x 1.68) = S/N in central pixel
> splot object[max / 2, *]
       > little e, little e on either side of peak
       > last number (flux)
       > sqrt (flux * 1.68) = S/N
Want > 100

Reduction Steps

HeNeAr wavelengths