To get the control programs running:

1. log into hydra@oatmeal
2. cd hydra
3. hydrawiyn
4. [in Hydra CLI] coldstart

During the observing run, following commands are used to operate the instrument:

• setup field

Move your .hydra files to oatmeal:/home/hydra/hydra/fields and type setup field. When prompted, enter the name of .hydra file with wanted fiber configuration. Decide on observing time for this setup and give siderial time of center of exposure. 

 

Current siderial time is given on status monitor above wiyn-2 monitors under LAST. Coordinate answering to other prompts with the observing assistant and wait for gripper to arrange the fibers (usually takes 20 – 25 minutes).

 

In the meantime, take note of gain, readnoise, binning and readtime values given in the camera control window (started by the observing staff). Fill in observer name(s) and set file name to ccd. Once the fibers are set, move the gripper out of the field usinggripout and get the fibers’ plate in focus with plate warp. To check if everything is alright so far, take a bias frame by setting exposure type to zero and title to bias (in camera window).

• setup flats

Let the operator know you want to take flat fields so they can turn on the lamp and set up mirrors to observe the screen (if making a dome flat). Take note of the number of counts from the lamp and adjust flat exposure time to avoid saturation and to have at least 30,000 counts in all fibers. Change the exposure type to flat and set title to the object name you’re observing. Keep the title for all the exposures made in this configuration, including flat, comparison and object exposures. Type setup flats and if cameras are off and telescope is in position, start the exposure.

• setup comps

To prepare measurement of comparison lamps, type setup comps. Take several short exposures (e.g., 3 s) to get good positions of bright lines, as well as several long exposures (e.g., 20 s) to measure fainter lines. Don’t forget to turn the lamps off when you’re done with complamp off or setup observe

• setup observe

To start scientific observations, type setup observe and move rotator to position. When setting a new field, view fop fibers (marked green) to ensure the tracking is working. If the weather is fine (check Mountain Weather , WIYN wind limit is 30 – 35 mph), you can start the scientific exposure.

• standard stars

Observe standard stars which are high above the horizon and relatively close together. Easiest way to select those is by searching for stars with R.A. similar to current siderial time and declination similar to latitude of the observing site. Next you can select suitable spectral and luminosity type stars (e.g., giants).

 

One way to observe standard stars is to move one of the fibers to center and point the telescope towards the star. First get the fiber plate flat with plate flat (required to be able to change fiber positions) and then get gripper in the field with gripin. Find a fiber number n with unobstructed way to the center of the field and type move n 0 0. When the fiber is moved take gripper out of the field with gripout and warp the plate with plate warp. Change the image title to the name of the star, set the exposure (usually very short, can be set to even less than a second) and make the observation. If you want to use more than one fiber, park the current fiber with park n.

Taken images are stored on cork in the directory listed in camera control window (e.g., /data1/observer/name). To copy the data use scp observer@cork.kpno.noao.edu:/path_to_data/*.fits. It’s a good idea to have more than one copy of the data.