Hallo Zusammen,
wer möchte könnte wieder aktiv werden und seinen persönlichen Beitrag leisten.
Gaia wird sich wieder von 42° auf 0 Grad gegen die Sonne drehen und somit ihre Helligkeit von 20.5mag um geschätzte 5 Größenklassen erhöhen. Der Sinn der Helligkeitsmessung besteht darin den Reflektionsgrad des Sonnenschildes von Gaia in bestimmten Ausrichtungspositionen zu bestimmen.
Hier anbei der original Artikel von Stefan Jordan, Dozent an der Uni-Heidelberg:
Dear All,
I am writing to you since you have participated in our „Gaia in the Sky“ project. Your contribution was extremely helpful to assess the brightness of Gaia.
Now there is a very interesting opportunity to help us again:
Tomorrow, February 26, at 11:58 UTC, Gaia will change its aspect angle with respect to the Sun from 42 degrees to zero degrees. This maneuver will take eight minutes. The exact times are
Slew SAA42 -> SAA0
starts: UTC 2014/02/26 11:58:52.815
ends: UTC 2014/02/26 12:06:43.815
We expect that Gaia will be considerably brighter than the current 20-20.5 mag after the move to zero degrees until it will again change its solar aspect angle to 45 degrees on Feb 27, 09:06 UTC. It is possible that Gaia will brighten by about than 5 magnitutes.
Slew SAA0 -> SAA45
starts: UTC 2014/02/27 09:06:43.478
ends: UTC 2014/02/27 09:15:11.978
The most interesting phase to take pictures and measure the brightness is the time of the maneuver itself because you could see the brightness varying on a time scale of minutes. For us data from this time period would be particularly useful because photometric measurents could tell us how Gaia’s sunshield reflects sunlight in different directions.
The time of the maneuver excludes observers from Europe, because the change of the aspect angle takes place during daylight at our longitudes. Nevertheless, observations from the night between Feb 26 and Feb 27 would also be very interesting.
Gaia’s ephemerides can be obtained at http://gaiainthesky.obspm.fr/fov/ .
This information comes on very short notice but the exact times of the maneuver were not available earlier.
Please send observations to Martin Altmann (maltmann(==>)ari.uni-heidelberg.de) and me (jordan(==>)ari.uni-heidelberg.de).
Best regards
Stefan and Martin
PS: Please forward this information to anyone who could be interested.
viel Erfolg!
Gruß Sascha
