Corot is a very nifty little satellite.

It is a french space agency small satellite, designed to measure convection, rotation and to find planets.

It started off as an astroseismology mission, in the Proteus class of standardised mini-satellite buses (hey! now there's a concept, standardized satellite buses for different class missions to reduce long term cost and enhance mission development... now if only someone else would do that, and stick with it for more than one funding cycle!).


It is tiny little thing, 300 kg, launched on a Russian Soyuz into a polar orbit, looking out orthogonally in the equatorial plane.
It has a tiny little telescope, 27 cm (just over 10 inches!), with a 4 CCD wide field detector.

Its primary mission, now, is to do high precision photometry of ~ 100,000 bright stars (12th-15th magnitude), to find transiting planets. It is sensitive to planetary transits down to planet masses somewhat bigger than the Earth (depends a little bit on the type of parent star).
It will focus on two fields - one towards the galactic center (in summer), and one towards the anti-center (during summerwinter).
Its main limitation is that it can only observe for a maximum of 150 days before it has to switch fields to avoid the Sun, and then it can revisit the field the next year (it actually also does "short looks" of 20 days).
So it is primarily sensitive to short orbital period planets, best at

The sensitivity is not maximal, Kepler, for example, will be sensitive to fainter variations in luminosity over a longer interval, and so will find smaller planets in longer orbital periods, but by the time Kepler flies Corot will have been collecting data for 2 years or so.
This, as I understand the history, is basically because Corot started off as an astroseismology mission, focused (like the Canadian MOST mission) on understanding stellar oscillations, primarily in nearby normal stars, but was adapted to be more optimised for transit searches as it became clear that that was a scientific priority.


Corot was launched in late 2006, promptly went to first light, and has been taking data.
The first "short look" was in february, and the data have been analyzed, and hopefully some results will be announced very soon.
They could be quite interesting results, Corot could see tens of obvious short period transits in its field of view, giving us a less biased sample of the mass and radius of the short period transiting planets. Over the next year, it should also gives us tens, or hundreds, of longer period transiting planets, depending on how planets are distributed in orbital period and mass around nearby stars.


More like this

In winter it looks at Galactic anti-center, I believe.

One thing I have been wondering about with transiting missions lately is the possibility of seeing a neutron star transit across a white dwarf. If it were a clean observation, you could get the radius of the NS. 15th magnitude is not deep enough, but Kepler might be able to do it.

It's not worth designing a whole mission for, but it might be something that you get for free with a mission like Corot or Kepler.

Of course, the "clean observation" part of it is tricky. Not only do you need to have the system close enough and oriented correctly, it also has to be quiescent and lacking significant winds.

Hm, I don't think Kepler will get there - I thinks its photometric accuracy is about 10 ppm which would be a little bit short of getting a NS-WD transit.
Also not a lot of those around. I think you need the next class of photometric missions after Kepler - sub micromagnitudes and much fainter targets.

Are you sure it's French and not Italian? It looks like a pizza oven.

By Mustafa Mond, FCD (not verified) on 01 May 2007 #permalink

Speaking of extrasolar planet survey satellites, I hope that the Microlensing Planet Finder or a similar mission will be funded. The telescope has the capacity to find planets in distant orbits which is not possible with other methods. In fact, the mission should be able to find even free-floating terrestrial planets.

By Dunkleosteus (not verified) on 01 May 2007 #permalink

I think NASA's only managed the "common bus" approach for two satellites at a time (Wind/Polar, RXTE/TRMM, etc.) I supported both Landsat-7 and Terra at different times, and you could not imagine two more different satellites functionally, even though they were both Earth observation missions being built by Lockheed Martin in their Valley Forge facility, with offices practically adjacent to each other.

Quick q: convection and rotation of what?

Specifically stellar rotation from periodic variations in brightness (eg modulation from starspots) and convection in the outer convective envelope leading to short period acoustic oscillations (astroseismology)

Not "into" the galactice center - rather some nice smooth field in the general direction towards the galactic center.
Their web page shows the field as a low res jpg, some papers on astro-ph also discuss characterization of the fields.
It is off Sagittarius towards Ophichus, squinting it looks like it is from the center of Sag by about one zodiacal constellation diameter, which is about 30 degrees.