January 2, 2017: Happy New year from TRAPPIST team !

November 20, 2016:
The "Amicale des belges du Maroc" visit Oukïmeden

This Sunday about 40 belgian people living in Morocco visited the new observatory of the Liège University.
A remote control of the telescope has been realised for them. Thank you to the local team for this nice afternoon !

October 15, 2016:
A new telescope in Morocco

On 6 October 2016, the new TRAPPIST-North telescope was inaugurated at the Observatory Oukaïmeden in the Moroccan Atlas. A Collaboration of researchers from the University of Liège and the Cadi Ayyad University of Marrakech, this telescope will observe for more than 250 nights a year exoplanets and comets.

October 6, 2016:
TRAPPIST-North Inauguration !

Today our new telescope, TRAPPIST-North has ben inaugurated at the Oukaimeden Observatory in Morocco in presence of scientists of the Cadi Ayyad University of Marrakech and astronomers from our University of Liège. TRAPPIST-North is the twin of the telescope that was installed in 2010 at the observatory of La Silla in Chile. It has the same goals as his famous predecessor: the detection and study of exoplanets, and the study of comets and other small bodies in the solar system to better understand the genesis of the solar system and our Earth in particular. The new telescope, installed in a record time in spring 2016, allows now the scientists of our team to have access to the whole northern and southern sky!

September 19, 2016:

Six years after his older brother TRAPPIST-South (TS) in la Silla whose code is I40, we are happy to report that TRAPPIST-North (TN) located at the Oukaimeden Observatory in Morocco is now part of the world list of the International Astronomical Union observatories, as Z53 ! We have now a webpage with live webcams and weather status

July 20, 2016:
TRAPPIST-1b and c planets are rocky and probably have compact atmospheres!

On May the Fourth, the Hubble Space Telescope observed the TRAPPIST-1 planetary system to catch a rare event: a double transit, the moment when two planets almost simultaneously pass in front of their star. These highly-precise observations have shown that the two innermost planets of the system are rocky, and that their atmospheres, if any, are likely not large and diffuse, like gas giants such as Jupiter, but instead compact, similar to the atmospheres of Earth, Venus, and Mars.

May 14, 2016:
First technical light of TRAPPIST-nord

On this day of Astronomy we are very happy to show you one of the first image taken with TRAPPIST-North ! After one month of civil work, 2 weeks of installation of the dome and the telescope, and one week of commissioning we got the first very promising images. Here 30 seconds on planetary nebula M27 with the V filter without any calibration. TRAPPIST-North, installed at the Oukaimeden Observatory in the Atlas montains of Morocco, will be ready soon to study the northern sky exoplanets and comets.

May 2, 2016:
Life elsewhere in the Universe? A new nearby planetary system could bring soon the answer...

With the ULg's robotic telescope TRAPPIST located in La Silla (Chile), three exoplanets similar to Earth have been detected. This discovery, issued in Nature, is a world first because the study of the atmospheres of these exoplanets is within the reach of telescopes, which finally makes it possible to search for life around another star.


April 25, 2016: Installation TRAPPIST-Nord telescope !

The installation of a new TRAPPIST telescope began in March at the observatory of Oukaimeden in Morocco. This April 25, an important step was taken with the installation of the dome!
TRAPPIST-N will, as its twin in Chile, be dedicated to the observation of exoplanets and comets and asteroids.

January 1, 2016:
The Antennae Galaxies

The famous Antennae is a pair of spiral galaxies that are interacting and mingling their stars. They began their galactic dance over a few hundred million years ago and are currently in a period where their colliding gas clouds are bursting with new star formation. As the two galaxies merge, their gravitational interactions pull long tails of gas away from each other, and these tails are the sites of starburst activity. This image was processed by Jean-Luc Mairlot and totalises 2 hours in each of the blue, green and red filters. Happy New Year to all !


November 12, 2015:
Earth-sized rocky planet orbiting a nearby star

TRAPPIST has been part of the discovery of a new rocky planet three times closer to Earth than any previously discovered Earth-sized planet and in orbit of a M-dwarf star. M-dwarf stars – hydrogen-burning stars that are smaller than 60% of the size of the Sun – are the most common class of stars in our Galaxy. Although the planet is too hot for human habitation, it is cool enough to support a substantial atmosphere and close enough for existing and upcoming telescopes to be able to observe the atmosphere's composition and dynamics. Stay tuned !
Zachory Berta-Thompson and colleagues from the MEarth project report in Nature their discovery of GJ 1132b

In this artist's rendering of GJ 1132b, a rocky exoplanet very similar to Earth in size and mass, circles a red dwarf star
© Dana Berry

November 1, 2015:
Halloween's 'Great Pumpkin' Asteroid

It is only a little bit scary but it's here in time for Halloween. A 400-metre-wide asteroid that scientists only spotted three weeks ago is going to shoot past Earth at 35 kilometres a second.
The large asteroid's trajectory will be just outside one lunar orbit, providing one of the best opportunities in years to gather very good data about a passing space rock. TRAPPIST has been following the asteroid for a few nights in order to get its rotation period while other observations were performed in parallel by NASA collaborators with an infrared telescope in Hawaii.

An asteroid will shoot past Earth at 35 km/s within 480,000 kilometres of Earth. (NASA)

October 28, 2015:
Comet 67P (Tchouri) from Earth: peak brightness and coma gases

While the Rosetta spacecraft is observing the comet from very close, the ground-based astronomers have been analysing from very far away the comet's brightness following perihelion – the comet's closest approach to the Sun along its orbit – on 13 August. Based on measurements made by TRAPPIST, the comet appeared to show the peak in brightness at the end of August. Indeed, data obtained by TRAPPIST on 31 August indicated a dust production rate at the nucleus corresponding to approximately 1000 kg per second. The peak brightness on the same day was recorded as magnitude 12 (roughly 250 times dimmer than the faintest stars visible to the unaided naked eye). TRAPPIST has also recorded the gas emission from the comet nucleus to derive the composition of the gaseous coma. Since the peak, the overall activity has reportedly been declining steadily, following the trend anticipated from observations made of 67P/C-G during previous perihelion passages.

More info on the ground based campaign on the ESA Rosetta blog :

CN emission (top) and dust emission (bottom) of Comet 67P/C-G on 22 August 2015 (© TRAPPIST)

September 30, 2014:
Discovery of two "hot Jupiters" around a binary system

TRAPPIST participated in the discovery of two new planets the size of Jupiter, each in very tight orbits of the two stars of a binary system. The majority of exoplanets known to date are orbiting single stars like our sun. However, 40-50% of stars in our Galaxy are part of multiple systems, most binary, formed from the same cloud of gas. Now, for the first time, two stars of the same binary system are known to house each a type exoplanet "hot Jupiter."

© Han Cheong Ho, Chungbuk National University, Republic of Korea

June 1, 2014:
TRAPPIST and comet 67P/Churyumov-Gerasimenko

The periodic comet 67P, which will be visited by the European space probe Rosetta in August is now observable with the telescope from Liège University. Located at a distance of more than 450 million km from Earth, or about three times the Earth-Sun distance, it is still a very weak target. It was necessary to combine several images to detect it. With a magnitude of 21.5 the comet is in fact 1.5 million times weaker than the faintest stars visible to the naked eye! TRAPPIST will regularly observe the comet until its closest approach to the Sun in August 2015 in the framework of an observation ground campaign to complement the data from the spacecraft. Stay tuned!

Comet 67P on April 28 2014 (© TRAPPIST)

March 26, 2014:
TRAPPIST involved in the discovery of a new planetary ring system

Observations made in various South American sites, including the La Silla Observatory in Chile with the robotic telescope TRAPPIST from Liège, revealed the existence of two amazing dense and narrow rings around the asteroid Chariklo. This distant body is currently the smallest object with a ring system, and only the fifth object in our solar system after the giant planets Jupiter, Saturn, Uranus and Neptune to show such a feature. The origin of these rings remains unknown to this day, it could be a disk of debris resulting from a collision.
These new findings will be published in the online edition of the journal Nature March 26, 2014.

Chariklo and its rings (© ESO)

January 15, 2014:
TRAPPIST detects a planet in the process of dislocation

We now know many cases of giant exoplanets orbiting very close to their stars. An extreme example of such a "hot Jupiter" has been discovered from Chile by the robotic telescope TRAPPIST, in collaboration with the English WASP project. The planet in question, WASP-103b, is orbiting its star at less than three stellar radii ! This extreme proximity generates huge tidal forces which pull strongly the planet, condemning it to an inevitable dislocation whose first manifestations may already be observable. The paper presenting this discovery has just been accepted for publication in Astronomy and Astrophysics.


November 18, 2013:
Comet ISON outburst !

Comet ISON was first spotted in the sky in September 2012 by amateur astronomers, and will make an extraordinary close approach to the Sun in late November 2013. Many astronomers believe ISON will then be one of the greatest comets of the last decades if it survives this encouter ! TRAPPIST has been monitoring the comet since mid-October, using special filters which isolate the emission of various gases, allowing our team to determine its chemical composition. During this survey, a giant outburst that shook the comet was identified on Nov 14, increasing the quantity of gas and dust ejected in space by a factor of ten. After several months of quiet activity, ISON finally woke up and is getting brighter every day. It is now bright enough to be seen with a good pair of binoculars from a dark site, the morning sky towards the East, and it will maybe be a great comet in December ! But with comets you never know...

Comet C/2012 S1 (ISON) on Nov 15 2013 (© TRAPPIST)

October 23, 2013:
Eleven new planets for TRAPPIST, and more than 1000 known exoplanets!

TRAPPIST has participated to the detection of 11 new transiting planets by the WASP transit survey. These 11 new planets bring the count of known exoplanets over a thousand, less than twenty years after the first exoplanet detection. The scientific papers presenting these new detections are available here:

May 7, 2013:
Occultation of a star by Pluto from Morocco.

Saturday, May 4 around 8:30 am from Morocco, astronomers Emmanuel Jehin, Cyrielle Opitom and Alice Decock observed remotely the occultation of a star by the dwarf planet Pluto. They were indeed in Marrakech for the astronomy school OISA 2013 on small Solar System bodies (comets, asteroids...). Before astronomers and students, they took control of the TRAPPIST telescope and managed to observe live this very rare phenomenon, demonstrating the capabilities of this 60 cm instrument, based at the La Silla Observatory in Chile, under full remote control.
The light curve of almost 5 minutes shows nicely the very thin atmosphere of Pluto (progressive decrease in brightness of the star light) which, thanks also to other observations made at the same time at the ESO VLT on Paranal and on other sites in South America, will allow to study the evolution of the atmosphere of Pluto, discovered in the 80s.

Light curve of the star occulted by Pluto (© TRAPPIST)

April 24, 2013:
A harvest of exoplanets for robotic telescope TRAPPIST.

Among the many planets detected orbiting other stars (exoplanets) over the last twenty years, a little less than three hundred periodically pass in front of their star. This is what astronomers call a planetary transit. One of the scientific objectives of Liege TRAPPIST telescope is the detection and study of exoplanets via the accurate measurement of their transits. In just three years, TRAPPIST has fully demonstrated its great potential in this area. Indeed, TRAPPIST participated in the detection of thirty planets, which represents 10% of all transiting exoplanets known to date!
The journal Astronomy and Astrophysics has just published an article on the last two exoplanets co-detected by TRAPPIST.

"Family Portrait" of planets co-detected by TRAPPIST with their relative sizes compared to those of Jupiter, Neptune and Earth-like planets. The temperature of the planet is higher when the color is redder.

April 2, 2013:
TRAPPIST reveals fast-evolving clouds for our new neighbor.

The detection of a binary system at only 6.6 light-years from Earth, the third closest system to the Sun, was announced recently. This amazing new neighbor is composed of two brown dwarfs, i.e. substellar objects which, unlike stars, are not massive enough to sustain nuclear reactions in their cores. These two brown dwarfs, known as Luhman-16A and B, orbit each other with a period of about 25 years. Given their "low" temperatures ~1200K, their atmospheres are potentially harboring unstable cloud systems able to create significant brightness variations within a timescale of a few hours. Using TRAPPIST to monitor intensively the system for 12 full nights, we have confirmed this theoretical prediction for the coolest component of the pair. Our data show not only complex quasi-periodic brightness variations with a period of ~5h corresponding to the rotation of the brown dwarf (these objects rotate as crazy), but also a strong night-to-night evolution that reveals a dramatic instability of weather patterns in the brown dwarf atmosphere. This is the first time that such rapid evolution is reported for the cloud coverage of a brown dwarf. The paper describing this nice discovery has just been submitted to the scientific journal Astronomy and Astrophysics.

January 15, 2013:
Asteroid Belgica is a binary.

TBased on a month of photometric observations, astronomers have discovered that the asteroid (1052) Belgica is double, with a rotation period of about two days. Some see it as a premonition of the split of our country. Belgica was discovered in 1925 in Uccle by Eugène Joseph Delporte. There is also an asteroid Wallonia (3198), discovered by François Dossin from Liege in 1981 at the Haute-Provence Observatory. Asteroid (1052) Belgica photographed January 9, 2013 with the TRAPPIST telescope. Superposition of five 2 minutes exposures showing that the asteroid moves on the starry background due to its motion around the Sun.

Asteroid Belgica moving in a star field (© TRAPPIST)

November 21, 2012:
Distant frigid world Makémaké reveals its secrets for the first time

Thanks to the TRAPPIST telescope observations, which was associated to the giant telescopes of ESO in Chile (VLT), researchers know more about Makemake, this enigmatic dwarf planet, that witnessed the formation of the solar system 4.6 billion years ago. To do this the team was able to observe an extremely rare event: the disappearance of a faint star (for almost a minute), because of the transit of the small planet just in front of the star. By combining these observations with those of six other telescopes in Chile and Brazil, the size of the dwarf planet located at 7.8 billion km, could be determined within a few kilometers (1502x1430km)! These observations also allowed to exclude the presence of an atmosphere even if, given its similarity with Pluto, one was expecting that Makemake had one. A surprising result which shows that we are still far from understanding the composition of these distant worlds.
The work of the international team of astronomers led by José Luis Ortiz (Instituto de Astrofisica de Andalucia, CSIC, Spain) have just been published in the journal Nature.


October 15, 2012:

A new webcam has been installed to watch TRAPPIST live from outside and check the sky.

October 10-25, 2012:

Technical mission in la Silla in order to upgrade the instrumentation : installation of two new filter wheels, a new focuser and a new secondary mirror.

Septembre 24, 2012:
New Comet ISON may Become "One of Brightest in History"

This newly discovered comet (24 Sept) could put on a dazzling celestial display late next year, when it will be so bright you may be able to see it briefly in the daytime sky ! At its perihelion, due on Nov. 28, 2013, the comet will come within only 1.2 million km of the sun's surface (it is called a sungrazer comet) and could evolve into a very bright object. The comet will then move to the north after perihelion and become visible during December both in the evening sky after sunset and in the morning sky before sunrise. Just how bright it will be and how long the tail may get during this time frame is anybody's guess, but there is hope that it could evolve into a memorable celestial showpiece.
A very exciting aspect of this new comet concerns its preliminary orbit, which is similarto that of the "Great Comet of 1680." The fact that the orbits are so close seems to suggest Comet ISON and the Great Comet of 1680 could be related or perhaps even the same object.

March 2012:
Technical mission in la Silla

View photo Gallery

November 8, 2011:
Asteroid 2005 YU55 came very close to Earth!

2005 YU55 came in the night of November 8 to 319 000 km of the Earth's surface, less than the distance from Earth to the Moon. Its speed is estimated to 46 600 km / h. This asteroid is on an orbit that passes at regular intervals in the vicinity of Earth, Venus and Mars. But Tuesday, it did the closer approach to our planet for at least 200 years. The next time an asteroid as big should come within a distance comparable to the Earth will be in 2028. Radar images show a spherical body 400m diameter. One of our objectives with TRAPPIST beeing the study of small solar system bodies, we joined an international observing campaign to characterize this body. We were able to follow the asteroid for several hours during this close encounter at high speed and take hundreds of images. The image shows the asteroid in the center of the field. The exposure time is 10s, and the telescope is traching the asteroid, so the stars are trailed.

Near Earth asteroid 2005 YU55

October 27, 2011:
Eris, unveiled by TRAPPIST telescope

This is a unique event that we had the opportunity to observe November 6, 2010 with our robotic telescope, TRAPPIST, installed at the La Silla Observatory in Chile. The dwarf planet Eris, the body most distant in the solar system, located 14 billion km from the Sun or three times farther than Pluto, fell right in front of a star whose brightness went off for about thirty seconds (news 06 Nov 2010). Unlikely event, this stellar occultation, also observed from another site in northern Chile was used to measure the size of the distant planet with unprecedented accuracy (1163 +-6km radius). This result is published today in the journal Nature (Sicardy et al. 2011). Eris is spherical and finally the same size as Pluto (1150-1200 km) and not bigger as astronomers beleived since its discovery (which led to the demotion of Pluto as a planet in 2006). Eris density has been revised upwards: it is a small rocky planet (85%) and not a Panet made of ice like Pluto. This has implications to understand the formation of the solar system. Finally, the surface of Eris has an albedo of 96% which is one of the most reflective in the the solar system! While similar to Pluton about the surface composition, Eris has no atmosphere. It has most probably making it looking like a mirror.


Paper in Nature :
ESO Press Release :
Paper published sur le site Réflexions from the Liège University :
Sky & Telescope :

August 23, 2011:
Replacement of the dome track (18-31 August 2011)

View photo Gallery

June 7, 2011:
The double occultation of Pluto and Charon of June 4, 2011

This June 4, 2011, the TRAPPIST team did a unique and very difficult observation ! We managed to observe the dwarf planet Pluto and its moon Charon passing in front of a very faint star. The observations were performed remotely from Belgium by E. Jehin using TRAPPIST, a 0.6m robotic telescope installed in 2010 at the La Silla Observatory in Chile. Charon was the first to hide the star for about 50 seconds at 5:30 UT, and about 12 minutes later, Pluto masked the same star during 2 minutes. The light curve of high quality (see figure below) shows the two events and reveals the striking difference between a body with an atmosphere (Pluto) and without atmosphere (Charon). Pluto's atmosphere is actually detected up to an altitude of several hundreds of km from the surface of Pluto. It is the first time a double occultation is observed from a single location. The phenomenon has been observed in two other sites in South America (at the SPACE observatory located in San Pedro de Atacama in Chile and at the observatory "Pico del Dias" in Brazil). These observations are part of an international campaign led by a team from Paris Observatory (Sicardy et al.). The comparison of these various data sets will provide valuable information on the parameters of the orbit of Charon, the size of each object and the atmosphere of Pluto. TRAPPIST had already succeded on Nov. 6, 2011, to observe the first occultation ever recorded of the dwarf planet Eris (E.Jehin et al. IAUC 9184; Sicardy et al 2011, submitted to Nature).

Light curve of the occulted star (red) showing two drops of flux. The first, with a square box shape, is due to the satellite Charon, whose size is estimated to about 1200 km. The second, twice as long, is due to Pluto that has a diameter of approximately 2350 km. The curved shape of this occultation reveals the presence of Pluto's atmosphere which refracts the light from the occulted star. The blue curves are the reference stars and are used to control the transparency of the sky which was excellent.

April 15, 2011:
Two new asteroids discovered by students at the University of Liège

As part of an astronomy course on small solar system bodies (comets and asteroids), given by E.Jehin for the Master is astrophysics of ULg, students from the University of Liège discovered two new asteroids. It was in the lab using the robotic telescope TRAPPIST, located in Chile, that this discovery was made. After having followed several nights and hainge calculated their orbits, these asteroids were confirmed by the International Astronomical Union.. They were given provisional names K11FE9A (or 2011 FA149) and K11FE9B (or 2011 FB149). Both asteroids are in the main asteroid belt between Mars and Jupiter. The first measures a mere 1 km in diameter and the second could be as large as 4 or 5 km. They rotate respectively in 4.2 years and 5.6 years around the Sun at average distances of our star of 390 and 470 million km. Before a final name will be given they must be observed again in the coming years when they will come again in opposition with the Sun.
Congratulations to Valentin Christiaens, Marc Levesque, Cyrielle Opitom, Laetitia Delrez, Lorraine Braibant and Emilie Gloesener.

The images of the discovery of the asteroid K11FE9A on March 31. We can see his movement among the stars during this sequence of images of 20 minutes.

March 16, 2011:
First participation of TRAPPIST to the detection of an exoplanet

TRAPPIST has contributed to the detection of the exoplanet WASP-23b. This planet is a gas giant very similar in size and mass to Jupiter. It orbits at less than 0.04 astronomical units of its host star, a dwarf star cooler and smaller than the Sun located about 600 light-years in the austral Puppis constellation. The TRAPPIST data have confirmed the existence of the planet, first detected by the WASP survey, and were used to measure precisely its size.
For more details, see

Transit of the WASP-23b exoplanet (Triaud et al. 2011)

February 14, 2011:
TRAPPIST observatory code is I40

Today the Minor Planet Center attributed the observatory code I40 to TRAPPIST !

February 2, 2011:
TRAPPIST recovers comet 9P/Tempel 1

This tiny fuzzy spike of light, lost in a rich field of the Milky Way and 10000 times fainter than the faintest stars visible to the naked eye, is periodic comet 9P/Tempel 1. This comet was the target of the NASA Deep Impact mission in 2005 which dropped a 500 kg copper bullet on its nucleus in order to study the material released by the blast.
About 6 years later, on February 14, the 9P ~5km nucleus will be revisited by the Stardust Spacecraft that collected several years ago dust grains in the tail of comet 81P/Wild 2.
A similar story happened a couple of months ago with the Deep Impact spacecraft itself that has also been rerouted to fly above the comet 103P/Hartley2 nucleus on November 4, providing spectacular images. One of the goal of the new mission of the Stardust spacecraft will be to take pictures of the crater, not seen yet, formed by the 2005 Deep Impact. Currently at 2.6 AU from the Earth and lost in the glare of the rising Sun, these images of the comet have been taken by the new belgian telescope based in la Silla Observatory (Chile).

Comet 9P/Tempel 1 moving among the stars

December 21, 2010:
The asteroid that wanted to be a comet

On December 11, asteroid (596) Scheila was discovered to have a small coma like a comet. There is a claim since a few years that comets are hiding in the main asteroid belt . Those so-called Main Belt Comets (MBC) would in fact be a newly discovered population of comets that formed in the outer edge of the Main Asteroid Belt. A few of them have been discovered and there could be thousands of them but still to discover. They are difficult to find because they are very weakly active. There is also the recent observation that big asteroid Themis has ices on its surface. These observations are very interesting because they show that comets and asteroids might not be exactly like we think and there might be more links between them than we thought before.
Is asteroid Scheila a MBC ? A very important observation to decide would be to discover if there is gas in its coma. Indeed comet activity is triggered by the sublimation of water and other ices like CO an CO2 by the Sun light. So far none of the MBC have been observed to have gas and some people claim that those objects are in fact activated asteroids for instance after a collision with a smaller asteroid.
We have been observing Scheila for a week with TRAPPIST using our narrow band filters and no gaseous species has been detected ! This is confirmed from deep spectra taken by our team at the ESO Very Large Telescope and still to be published. Scheila, like the object P/2010 A2 observed earlier this year, does not seem to be a comet. The coma is most probably rather resulting from an asteroid-on-asteroid impact. The coma is indeed vanishing in space from day to day and there is no sustain activity. Stay tune for more information !

(596) Scheila
Jehin, E.; Manfroid, J.; Hutsemekers, D.; Gillon, M.; Magain, P.

Asteroid Scheila surrounded by a dust cloud

November 6, 2010:
TRAPPIST and dwarf planet Eris

A first was achieved on the night of November 6 with TRAPPIST ! Emmanuël Jehin became the first astronomer to observe a stellar occultation by the dwarf planet Eris. This planet occulted a 15 magnitude star for a period of 30 seconds. This unlikely observation, combined with that also carried out in San Pedro de Atacama by Alain Maury and his team, will enable the size of Eris to be measured to within a few dozen kilometres or so. Up until now its size was only known within a range of some hundreds of kilometres! The observation of this occultation is the longest ever to have been carried out: a distance of 14 billion kilometres (three times as far as Pluto).

Emmanuël Jehin & others / TRAPPIST Observatory
E. Jehin, J. Manfroid, M. Gillon, D. Hutsemekers, and P. Magain, ?Occultation by (136169) Eris?, 2010 IAUC 9184.

Images taken every 4,5 seconds clearly show the brief disappearance of a star behind the dwarf planet Eris on November 6, 2010 (Universal Time).

November 4, 2010:
Comet Hartley2 observing campaign

TRAPPIST is part of an international observing campaign to observe the Jupiter Family comet 103P/Hartley 2 that has just been flew by the NASA EPOXI spacecraft today. Spectacular images have been sent to Earth by EPOXI showing strong jets coming from a very small (2km) pinut shape nucleus.
The many TRAPPIST observations through special filters that are collected every day during this period are used to derive the composition of the comet and to follow its activity.
A rotation period of the nulecus of 18.2 hours has been found as well as a braking of the rotation speed with time.

Jehin, E.; Manfroid, J.; Hutsemekers, D.; Gillon, M.; Magain, P, "Comet 103P/Hartley", 2010 CBET 2589

Comet 103P/Hartley2 on Oct. 31 through the various narrow band cometary filters (from left to right the images reveal the distribution of the radicals OH, CN, C3, C2, GC and the ion H2O+)

June 8, 2010:
TRAPPIST First Light !

Our new robotic telescope has had its first light at the European Southern Observatory's (ESO) La Silla Observatory in Chile last night. The TRAnsiting Planets and PlanetesImals Small Telescope (TRAPPIST) is devoted to the study of planetary systems through two approaches: the detection and characterization of planets located outside the solar system (exoplanets), and the study of comets orbiting around the Sun. It is a 24-inch (60 centimeters) robotic telescope which is operated from a control room in Liege, Belgium, 12,000 kilometers away.
The first light was done from the Liège University downtown with Bernard Rentier the rector of the University, Didier Queloz from Geneva Observatory, the TRAPPIST team and journalists. Control of the telescope was taken and the first light has been done on the famous Tarentula Nebula in real time.

TRAPPIST first light image of the Tarantula Nebula in the Large Magellanic Cloud.