Observing Procedures
This is when we begin observations, in good conditions.
What is 20 minutes before 12 degree twilight?
To within 2 degrees, this is the latitude of Keck Observatory.
19.8 degrees N.
These are the CPS names of the three HIRES CCDs, in order from longest wavelength to shortest.
Red, iodine/middle/visible, blue
The name for this optical element comes from the French word for "ladder."
What is echelle?
This observatory was the first to use segmented primary mirrors.
What is the W. M. Keck Observatory?
This is the state of the iodine cell for observations of B stars during a template sequence.
What is in?
At LST 17:00, a star with coordinates RA= 20h and Dec = +20 degrees is in this cardinal direction.
What is East?
This element produces a triplet of spectral lines near 5170 Angstroms that are used to measure stellar log(g).
What is magnesium?
This optical element picks off a small fraction of the incoming photons and sends them to a photo-multiplier tube to count them in real time.
What is the exposure meter?
This telescope is nearest to Keck Observatory.
What is Subaru?
What is B5?
This is a star's elevation above the horizon, to within 1 degree, at airmass 2.
What is 30 degrees?
This line from the Balmer series is often used as observatory door access codes and is situated on the HIRES red CCD. Name the element, transition, and wavelength (to the nearest Angstrom).
What is H alpha at 6563 Angstroms?
This optical element switches whether light comes from the lamps or the HIRES slit.
What is the calibration mirror?
The world's > 10m diameter optical telescopes include Keck I and II, the Hobby Eberly Telescope in Texas, SALT in South Africa, and GTC, which is a telescope on this archipelago.
What are the Canary Islands?
During a template sequence, we change these attributes of the HIRES optical path between the observations of the B stars and templates.
What is the iodine cell (and nothing else)?
At LST = 2:00, a slew between Star A (RA=22 hr, Dec=+90 degrees) and Star B (RA=02 hr, Dec=+10 degrees) takes this long, assuming Keck slews 1 degree per second (to the nearest minute).
What is 180 seconds (3 minutes)?
In the wavelength direction, each HIRES pixel corresponds to this many Angstroms (to one significant figure).
What is 0.1?
To ensure the guiding is based on wavelengths of starlight matched to the middle (iodine) chip, this filter should be used in front of the guide camera.
What is bg38?
This observatory collected the data that was published in the first paper announcing an exoplanet around a main-sequence star.
What is the Observatoire Haute-Provence / Swiss Telescope?
It takes this long to observe a 12th magnitude star to achieve SNR=200, assuming we achieve the same SNR on a 7th magnitude star of the same spectral type in the same conditions in 1 minute.
What is 100 minutes?
At LST=02:00, a slew between a Star A (Azimuth=-20 degrees, Elevation=35 degrees) and Star B (Azimuth=+220 degrees, Elevation=20 degrees) takes this long, assuming Keck slews at 1 degree per second.(to the nearest minute).
What is 240 seconds (4 minutes)?
This function describes the shape of the intensity versus wavelength in each spectral order.
What is the Blaze function?
This optical element spatially separates the spectrum into multiple orders.
What is the cross-disperser?
ESPRESSO is mounted at this southern observatory.
What is the Very Large Telescope (VLT)?