Image Credit: ESA GBOT (ground based observation tools) FOV output for the 2nd tilt on 27th Feb developed by S. Bouquillon & T. Carlucci utilizing Stilts , Aladin , ESO online digitized Sky Survey , CDSclient.
Amateur astronomers tonight are chasing the Gaia Glint.As the Gaia spacecraft rounds the L2 Lagrange Point tonight on its mission to create a 3d map of our solar system, around 10:45 Local time [11:45 UT] the solar panels will turn back around to "flash" earth for about 24 hours. Sadly the weather is looking poor at two of iTelescope.net's sites. The ESA mission controllers have asked for a light curve of the turn. Easy peasy .... or so it seems. The targeting is not the issue, the spacecraft will cruise in at Mag 20 to 20.5 and then over a period of 15-20 minutes will brighten to magnitude 15. Whilst magnitude 15 is within reach of most amateurs with sophisticated goto scopes, Mag 20.5 is a different prospect, requiring probably a few stacked images as it brightens. So its going to be hard to make it look any different to "off" & "on" and trap the subtelties of the rising magnitude. Never one to shirk a challenge we'll give it a go. If not we can have another go tomorrow night as the spacecraft turns again and the reverse happens (fades from Mag 15 to 20). I'm sure someone will catch it, there are a couple of others I know who are chasing it. The spacecraft is going through some very detailed and precise commissioning tests as it orbits the L2 Lagrange point. When fully operational the spacecraft is required to maintain a constant spin rate of 0.016656 degrees per second, which is one rotation every 6 hours & 14.23 seconds. One of the comissioning tests was to put the spacecraft through a tilt from 0 to 45 degrees and back again, and like all good scientists they wanted an independent source of data to confirm the tilt process was completed properly and smoothly, and confirmed by their on board instruments as well as visually. Amateur astronomers are always up for a challenge and like to assist and be involved in the mission.