a medley of science images

A few science projects on which I haveworked while at CFHT..

This page will highlight some of the areas I have worked in while at CFHT. Many of those started in my early years. As I got involved more and more in big projects (like MegaCam/MegPrime or the CFHTLS) and CFHT management work, I spent less time on scientific endeavors.

Recovery of Kuiper Belt objets

By the end of 1996, Kuiper Belt Objects were still a new topic and there was a need for follow-up on the objects discovered by a few programs going on on other telescopes. Finding new ones was very important, but a good orbit for each of them was key to the understanding of the dynamics of this area of the Solar System beyond Neptune. Mainly using MOS in imaging mode and later CFH12K, I recovered many KBOs and discovered a few on the way. I slowed down the project when larger programs and surveys were proposed by PIs and scheduled on the telescopes. These early years of KBO observations are summarized in an old web page here

Discovery of the first binary Kuiper Belt object

While observing 1998WW31, a KBO discoverd a couple of years earlier and in need of recovery, I discovered that it looked like a pair of objects traveling together. More observations confirmed that indeed it was so! The chances to have this happening without the two objects actually being bound were slim, but it could not beruled out... Digging in the CFHT archive led to a few more images from the previous year, which indeed showed a pair of objects, this time closer and not with the same orientation. The rest of the story can be found here and the Nature paper here.

Follow-up and recovery of Near Earth Asteroids (NEAs)

Near Earth Asteroids (NEAs) are asteroids with an orbit thath can bring them close to the Earth's orbit, and then potentially to the Earth itself. NEAs are discovered generally when close to the Earth, where they are bright and have an apparent fast motion. They are then easy to detect among the other more classical asteroids. Dedicated observing programs on a few telescopes around the world make most of the discoveries of the NEAs. Very quickly they become difficult to observe, as their distance from the Earth is rapidly increasing, making them too faint for most of the instruments used in the asteroid observation community. This is where a larger telescope, with the possibility of tracking a moving object, is needed to observe more and then enable the computation of a better orbit. CFHT is excellent for that kind of tracking, able to track at the projected rate of the asteroid. I maintained a program of recovery of NEAs in my early years at CFHT... These observations are summarized in an old web page here

Confirming the discovery of the first true co-orbital companion of the Earth

With quite a few NEAs recovered or followed-up in an efficient way in the previous years, I was ready to jump on a strange object which potentially looked like a companion of the Earth, pointed out by colleagues from Canada with whom I had worked on asteroid observations. 2002_AA29 had been discovered in January 2002, and we could follow it up for long enough to be able to extend the arc of observations from 16 days to one month, confirming the nature of its orbit. 2002 AA29 is a very interesting object! You can find a wealth of information here.

Follow-up observations of gamma-ray bursts

This was an activity of my early days at CFHT, when not that many telescopes were ready to spend time to observe the optical counterpart of gamma-ray bursts. This activity led to a good cooperation with French colleagues and a couple of regular PI programs in addition to using Discretionary Time when a GRB was in need of follow-up on a realtively "big" telescope. More on these observations can be found here.

Observation of the crash of Smart-1 on the Moon

When the European Lunar orbiter Smart-1 was scheduled to end its mission through a controlled crash in an area of the moon not illuminated by the Sun and visible at night from Hawaii, the observatories were asked by the ESA Smart-1 team to attempt to observe the flash the impact should create. None of the telescopes, but for the NASA IRTF, was keen to do anything and I decided to seize the opportunity to come back to the Moon with a telescope (I had spent 12 years ranging the Moon in my previous position in France). It worked very well, using WIRCam and the narrowest available filter.

The animation on the left shows the bright flash (upper right corner, close to the top of the picture) on one of the images of a sequence showing part of the Moon wandering in front of the stars. It was the first time that a crash and the subsequent plume of ejecta were observed. The CFHT observations of the crash are described here.