The UniversCity telescope, whose construction is being finalized at Plateau de Calern, was used to obtain scientific data on occultations for the first time on July 10, 2021, by a remote observer. Both observations (the first one in the early hours of that day, the second on the following night), turned out to be positive thus producing useful measurements. They concerned the asteroids (2207) Antenor and (884) Priamus, trojans of Jupiter and selected targets of the Lucky Star project (https://lesia.obspm.fr/lucky-star/index.php).
The observations were executed by Luana Liberato, PhD student (UMR Lagrange / UNESP – Brazil), who was trained and assisted for taking the remote control of the telescope by Paul Girard (project manager of UniversCity, Côte d'Azur Observatory) and Erick Bondoux (OGS Technologies).
For the two events, the probability of getting the occultation was between 15% and 40% with the nominal shadow of Antenor not passing over the Calern site. These detections will much improve the orbit accuracy and more information on size and shape are obtained by coupling them to results obtained from other sites, including two others by our team: from the Schaumasse telescope (Mont-Gros, Nice, by Matthieu Conjat) and from a movable station (Paolo Tanga).
The UniversCity telescope is 0.5 m in diameter, and one of the main applications that drove its design is the systematic observation of stellar occultations by minor planet, in robotic mode, by exploiting the improvements brought by the Gaia mission.
Remote operations are a first, preliminary step towards the automation of the telescope.
The plots show the measured signal for the stars occulted by Antenor (top) and Priamus (bottom). Both events were low in elevation and the second one was affected by heavy veils. The black dots represent the observed data, the red ones are the fitted model
(© L. Liberato, UMR Lagrange, CNRS-UCA-OCA ).
The sky-projected shape of Antenor obtained from its occultation. The positive occultation observations from different locations provide 4 “cuts” through the shape (named “chords”), reconstructed on the sky plane from the knowledge on the observer locations, the timing of the occultation, and the motion of the asteroid on the sky. The continuous lines corresponds to locations were the occultation did not occur. The resulting best-fitting ellipse (black line) has largest radius of 63.1 4.9 km and flattening of 15 7 %. The grey area represents the uncertainty on the shape.
(© L. Liberato, UMR Lagrange, CNRS-UCA-OCA – package SORA – UniversCity, Observatoire de la Côte d'Azur).
The moons of planets that have no parent star can possess an atmosphere and retain liquid water. Astrophysicists from Ludwig Maximilian University of Munich, University of Concepción in Chile, Lagrange Laboratory, and University of Tokyo have calculated that such systems could harbor sufficient water to make life possible – and sustain it.
Lagrange laboratory is recruiting an engineer in Software engineering.
Lagrange laboratory is recruiting an engineer in Instrumental development.
The 2021 Olivier Chesneau Prize has been awarded to Mathias Novak for his doctoral work entitled : «The 2017 conjunction of Beta Pictoris b: the Life and Death of PicSat, followed by a VLTI/GRAVITY observation of the re-emergence » that was successfully defended in 2019 at the Observatoire de Paris.
Undismayed by the loss of the PicSat satellite which was the centerpiece of his planned doctoral work, two years into the works, Mathias was able to switch gears, while keeping his objective. He started to work on the then newly commissioned GRAVITY instrument at the focus of ESO's Very Large Telescope Interferometer. Taking advantage of his practical experience with the problem of injection of light into single-mode fibers, acquired while working on PicSat, he was able in a very short time, to make technical contributions that led to improving the astrometric capability of GRAVITY. Building up from there, he joined the exoplanet program of GRAVITY, where his data processing skills contributed to the first GRAVITY observation of the exoplanet HR 8799e. He was eventually able to close the circle of his doctoral work by finally observing Beta Pictoris: he produced the first very high quality spectrum of Beta Pictoris b, and ultimately, led the first direct detection of Beta Pictoris c, a planet that had only been indirectly detected by radial velocity. Overall, this work has had a major technical and scientific impact in both the interferometry and the exoplanet communities.
These impressive achievements, owed to a deep understanding of technical issues and their consequences on astrophysical measurements, combined with resilience of face of adversity, are the hallmark of the spirit of the Olivier Chesneau Prize, which this year's board of judges is absolutely delighted to award to Dr. Mathias Novak.
Illustration : Vue d'artiste Beta Pictoris B - © ESO L. Calçada/N. Risinger (skysurvey.org)
Apophis, an Earth-crossing asteroid, fascinates both scientists and public since it regularly encounters the Earth. It has passed at 16.8 millions km in March 2021, and in April 2029 it will come as close as 31000 km to the Earth surface (12 times closer than Moon). Its trajectory is thus under close surveillance since its discovery in 2004.
Two astronomy networks are coming together to form Europe’s largest ground-based astronomy collaborative network: the ORP. The ORP will provide scientists with access to a wide range of instruments, promote training for young astronomers, and open the way to new discoveries. The CNRS will be responsible for coordinating the ORP, which is supported by €15 million of funding from the H2020 programme.
Reaching new heights with 100 consortium publications including the early exoplanet demographics release.
An international team of astronomers led by researchers from the Netherlands has discovered a whirlwind of dust and pebbles in orbit around a young star. It is possible that a planet is forming in the pebbles. The team of scientists made the discovery during the time that designers and developers of an astronomical instrument get as a reward for their work. They will soon publish their findings in the journal Astronomy & Astrophysics.
The week of December 19, 2020 was the last nights of the CHARA/VEGA instrument, nights animated by Olli, Fred and myself.