How to go about ´rvcorrect´

newirafuser3 wrote on May 01, 2011

Hi, I´m trying to do heliocentric corrections on a set of frames (i.e. convert the JD values into HJD) I´ve looked into the task ´rvcorrect´.

I need to create an ASCII file with a row entry for each frame and in each row there will be UT,RA,DEC,EPOCH and observed velocity. The problem is creating this file.

I tried using imheader to extract these parameters for each frame and redirect it to a file, but it was a bit of a mess. I´m wondering how this is usually done and how i can go about creating such a file.

Thanks very much.

---

Mike Fitzpatrick wrote on May 01, 2011

RVCORRECT simply computes the various elements of the shoft corrections for a particular location/observatory/time, it doesn't actually modify the data. Are you just trying to compute the HJD time or are you actually trying to shift a spectrum to a rest frame? In the first case I'd suggest you look at the ASTHEDIT task, in the second see the SPECSHIFT task (help pages and examples). Otherwise, please provide more details about what you're trying to do exactly.

---

newirafuser3 wrote on May 01, 2011

Yes, thats correct, I wanted to computer the HJD time, using the data from the headers. I was convinced that rvcorrect would, after I read the following tutorial:
http://www.stsci.edu/documents/dhb/webvol2/c08_fosdataanal.fm3.html

I've now had a look at the ASTHEDIT task. but I couldn't find the astronomical function to compute the HJD.

---

Last post on May 01, 2011