Kast Observations, May 21 2013

While the weather has been looking good all day for tonight's run, the marine layer has moved in:

Courtesy of Pavl Zachary:

While it's pretty, it doesn't bode well for observing tonight. Humidity's up near 90%, which means we're teetering on the edge of closing the dome.

Calculating Rotational Velocities (vsini)

Now that I have a library of echelle spectra, I can measure rotational velocities for those stars without measurements in the literature.

To calculate rotational velocities from our Hamilton Echelle spectra, we will use the following technique from Fekel 1997:

Kast Observations, May 2013 (Night 3)

Tonight we will be focusing on our dimmer stars (Vmag~13-14), and thus will be observing fewer targets. It looks like we're going to have a full 4 nights of fair-weather observing (practically unheard of at Lick!). Tonight's seeing is ~0.7 arcseconds.

Kast Observations, May 2013 (Night 2)

Tonight, in addition to our own targets, we will be observing the AGN Zw 229-015 (AGN = Active Galactic Nucleus). By taking spectra using the Lick 3m telescope, the AGN team (Aaron Barth et al.) will be able to measure the Hbeta emission. This will help them to determine the mass of the black hole at the center of this AGN via a technique called reverberation mapping. 

Kast Observations, May 2013 (Night 1)

Our group has been granted 4 nights on the Shane 3m telescope at Lick Observatory on Mount Hamilton using the Kast Dual Spectrometer. Tonight we are observing a set of low-mass stars with little to no data in the literature to look for Ha in emission and strong lithium absorption (both signatures of youth). We can also look at the TiO bands (~7200 Angstroms) to get a better estimate of the spectral type.