(cba:news) [Fwd: GALEX observations of TT Ari] (Joe Patterson) [2009-11-13T22:30:01Z]
Dear CBAers,
Galex (an ultraviolet imaging/spectroscopy satellite) has scheduled some
target-of-opportunity time for TT Ari, from now until Nov. 27. Appended
is the schedule. Like nearly all science satellites, this is a
low-Earth-orbiter, hence the windows are all somewhat brief - but there
are many of them, and if you have clear sky coinciding with any of these
times, your observations will have very high scientific value. Under
these circumstances, it might well be best to use filters, to get truly
simultaneous measures of the continuum. (Hard to say for sure, though;
we'll know for sure after the data are in!)
joe
-------- Original Message --------
Subject: GALEX observations of TT Ari
Date: Fri, 13 Nov 2009 10:45:15 -0800
From: Karl Forster <krl@xxxxxxxxxxxxxxx>
To: jop@xxxxxxxxxxxxxxxxxx
CC: Karl Forster <krl@xxxxxxxxxxxxxxx>, Chris Martin
<cmartin@xxxxxxxxxxxxxxx>, kerry.d.erickson@xxxxxxxxxxx,
susan.g.neff@xxxxxxxx
Hi Joe,
It was good to see you again. Thank you for sending the request for
directors
discretionary time for observations of TT Ari. I agree, it is a unique
chance
to explore this CV in a "zero accretion" state.
With Chris's approval I have scheduled some GALEX observations of TT Ari for
next week and will continue with more observations until we loose visibility
on November 27th.
Here is the schedule of observations:
Eclipse Target_ID Survey OW_pos Start End
Exposure (seconds)
34933 TT_Ari ETI imaging 2009-11-14T18:26:41.2Z
2009-11-14T18:51:24.2Z 1480
34940 TT_Ari ETS grism 2009-11-15T05:53:58.5Z
2009-11-15T06:21:33.1Z 1650
34941 TT_Ari ETS grism 2009-11-15T07:32:32.6Z
2009-11-15T08:00:08.6Z 1650
34954 TT_Ari ETI imaging 2009-11-16T04:53:55.4Z
2009-11-16T05:21:48.1Z 1670
34955 TT_Ari ETI imaging 2009-11-16T06:32:29.5Z
2009-11-16T07:00:23.3Z 1670
34969 TT_Ari ETI imaging 2009-11-17T05:32:26.8Z
2009-11-17T06:00:34.9Z 1680
34970 TT_Ari ETI imaging 2009-11-17T07:11:00.9Z
2009-11-17T07:39:09.9Z 1680
34983 TT_Ari ETI imaging 2009-11-18T04:32:25.0Z
2009-11-18T05:00:44.0Z 1690
34984 TT_Ari ETI imaging 2009-11-18T06:10:59.2Z
2009-11-18T06:39:18.9Z 1690
34998 TT_Ari ETI imaging 2009-11-19T05:10:58.8Z
2009-11-19T05:39:26.3Z 1700
34999 TT_Ari ETI imaging 2009-11-19T06:49:33.1Z
2009-11-19T07:18:01.0Z 1700
35013 TT_Ari ETI imaging 2009-11-20T05:49:34.5Z
2009-11-20T06:18:07.4Z 1710
35014 TT_Ari ETI imaging 2009-11-20T07:28:09.0Z
2009-11-20T07:56:42.1Z 1710
Note: All time are UT
I also wanted to let you know that there have been a number of
GALEX exposures of TT Ari earlier in the mission:
Date Survey Target_ID Exposure
2003-11-22 AIS AIS_184_sg44 144s
2004-11-19 GII GI1_113009_TT_ARI 1467s
2004-11-19 GII GI1_113009_TT_ARI 1686s
2005-10-06 AIS AIS_184_sg44 112s (NUV only)
2005-11-02 AIS AIS_184_sg44 106s
2007-10-16 AIS AIS_184_sg44 106s
2007-11-04 AIS AIS_184_sg44 96s
Note that the GI observations were centered on the position of TT Ari
but the All sky survey observations placed the star approx 20 arcmin from
the center, still well within the field of view.
I noticed that the GI observations have a reflection feature in the
NUV exposure due to a star off the south edge of the field of view. To
avoid this I have moved the pointing center for the new observations
10 arcmin north. So TT Ari will be 10 arcmin south of the center of
the field of view.
I have also included a couple of grism exposures with dispersion
angles (PA East of North) 320 and 180 degrees. This will avoid
confusion with spectra from some of the nearby bright stars. All the
archive data is available at MAST:
HTTP://galex.stsci.edu/GR4/
except for the photon data which you will need if you want to explore
variations during an exposure (in the archived and new data we will
take).
Let me know if you have any questions or need more information.
thanks
Karl