P71-508 Spectroscopic Study of Asteroid Phase Coloring

ALFOSC spectroscopy of moving targets. SoftToO/ToO observations.

Instrument setup required for ALFOSC:

• Blocking filter: #100 (GG420_416_LP)
• Grism #11
• Slit: 1.8"

Observing instructions:

1. Go to the directory
     cd ~/scripts/71-508
   List the available OB scripts
     ls -lrt

2. Most likely there will be two OB scripts for the current trigger, one for the target and one for the standard (solar analog).
   Start the target OB script, when it tells you to do the pointing, go to step 3.

3. In another sequencer terminal run tcs.asteph as indicated by the PI in the OB comment.
   For completeness we show below the usage with all possible options (the first option in each flag is the default)

         tcs.asteph [ -t < asteroid|comet|planet|unconfirmed|horizons > ] [ -m < ima|para|along-slit|optimal-ll|optimal-lr > ]
                    [ -r < full|half > ] [-g < on|blind|update >] [-e INTIME] -n TARGET
         

   The PI is responsible for giving you the the exact input for tcs.asteph, and it is typically:
   • tcs.asteph -m para -n TARGETNAME
     
     
   Below is given in green an example of what tcs.asteph outputs on your terminal screen.

   EXAMPLE:
   > tcs.asteph -t asteroid -m para -n Vesta
   ...
   Your input target is                        -  Vesta
   Your observatory is Nordic Optical Telescope, La Palma.
   Today is  2025-03-07
   Your computer says time is  11:11  UTC.
   Retrieving data from JPL Horizons...
   Data retrieved successfully from JPL Horizons.
   The object being searched for is  4_Vesta_A807_FA
   Prefix for file names will be  2025-Mar-07.4_Vesta_A807_FA
   ***************************
   These tasks should be given to the TCS:
   ***************************
   tcs.append-object 4_Vesta_A807_FA-11 15 10 48.67 -07 22 59.8 2000.0 0.0 0.0 6.823
   tcs.ag-off
   tcs.guide-object-with-parallactic 4_Vesta_A807_FA-11
   tcs.reposition-guide-probe 17.9142 4.301609
   
   

4. Cut and paste the last 4 output lines in the sequencer window, one by one.
   When done, differential tracking and autoguiding has started.

5. Go back to the OB script and press return to start ALFOSC setup, slit acquisition and data taking.
   The slit acquisition is interactive, as usual. In order to locate the target, the NOT Aladin is useful.

6. Remember to run the OB of a solar analog. This is a normal OB.

• For more general information on how differential tracking/autoguiding works, see the section "Moving Targets" in the ALFOSC Cookbook.
• Please, fill in the ToO or SoftToO tracking log.

Should any of the observations have been carried out using the OB system, you will find additional information HERE