DISRUPTIVE PLANETS
discovering and studying new worlds to consolidate our understanding of planets and habitats.
Discover
The first essential step to astronomical study relates to discovering objects of interest. In this quest, our team aims at discovering exoplanets with the TRAPPIST and SPECULOOS telescopes, but also with TESS and GPX. These planets are found via the transit techniques, which means that their atmospheres can also be studied in detail via transmission spectroscopy notably with the Hubble and James Webb Space Telescopes. In addition, our team now leverages GPUs to mine for minor bodies of the Solar System crossing the field of views of the aforementioned observatories as bonus harvest!
Terrestrial Planets around Red Dwarfs
Ultra-cool stars are also ultra small, therefore it is easier to find and later study small planets around them than it is around larger stars such as the Sun. To this end, dedicated surveys such as TRAPPIST and SPECULOOS have been designed leading notably to the detection of the TRAPPIST-1 system.
Showcased Papers:
"Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1"
Gillon et al. 2017
"π Earth: a 3.14 days Earth-sized Planet from \textit{K2}'s Kitchen served warm by the SPECULOOS Team"
Niraula et al., 2020
Tools used in Quest: SPECULOOS, Kepler, Spitzer
The TRAPPIST-1 system was discovered with a 60-cm ground-based telescope named TRAPPIST and hosts seven temperate terrestrial exoplanets that are readily available for atmospheric characterization owing to the small (Jupiter-like) size of their ultra-cool dwarf star. Left panel: Phase-folded transit of the seven planets after monitoring with the Spitzer Space Telescope. Right panel: Representation of the orbits of the seven planets. The grey annulus and the two dashed lines represent the traditional habitable zone. Figure from Gillon et al. 2017.
Showcasing pi-Earth (aka, K2-315 or EPIC 249631677 b) amongst the most promising terrestrial planets for atmospheric characterization. Point colors illustrate the S/N of a JWST/NIRSpec observation relative to TRAPPIST-1b. The planets for which the presence of an atmosphere could be assessed by JWST within ∼50 transits are encircled in black.The size of the circle
is proportional to the size of the planet. Circles for 1.5 R⊕ and 1.0 R⊕ are drawn in the upper right corner for reference. Figure from Niraula et al. 2020
Gas Giants and Brown Dwarfs in Crowded Fields
In crowded fields, the point-spread-function of stars on the detectors overlap leading to dilution of the transit signal searched. In this subquest, efforts are made to enable detections in such fields to probe regimes of systems difficult to access otherwise
Showcased Papers:
Benni et al., 2021
Burdanov et al., 2018
Tools used in Quest: SPECULOOS, TESS, GPX
Introducing GPX-1, a young low-mass brown dwarf transiting a fast-rotating F-type star in the Galactic Plane. Detecting transiting companions in crowded parts of the sky, such as the Galactic Plane, is challenging for most missions due to their large pixel scale which results in blended stellar images and thus a dilution of the transit signal. Left panel: a 210 × 210 arcsec^2 region around GPX-1 as seen by SPECULOOS. Right panel: same region as seen by TESS. Figure from Benni et al. 2021.
Showcasing KPS-1, the first transiting exoplanet detected with an amateur astronomer's wide field CCD. This first discovery highlights the possibility of leveraging customer-grade astronomy equipment to find exoplanets in the galactic plane, which is generally out of reach for professional missions due to its crowdedness. Left: KPS-1 host star field. Right: Phase-folded lightcurve for KPS-1. Figure from Burdanov et al. 2018.
Harvesting Solar-System Minor Bodies as Bonus Science
Our exoplanet surveys observe fields of view for long periods of time (typically for hundreds of hours). Therefore, the observations made can be used for more than the search of exoplanets. An example of bonus science relates to searching for moving objects via a “shift and stack” that leverages GPU technology.
Showcased Papers:
“GPU-based framework for detecting small Solar system bodies in targeted exoplanet surveys”
Burdanov, Hasler, & de Wit 2022, MNRAS 521 (3), 4568-4578.
&
“Small body harvest with the Antarctic Search for Transiting Exoplanets (ASTEP) project”
Hasler, Burdanov, de Wit, et al. 2023, MNRAS 521 (3), 4568-4578.
Tools used in Quest: SPECULOOS
Left: Detection of the faintest (𝑉 =23.8 mag) unknown object in the SPECULOOS archival data. Stacked and shifted image is composed of 215 images in 𝐼+𝑧' filter with 72 s exposure time and obtained by the SPECULOOS' Ganymede telescope on 19 March 2020 in Sp1444-2019 field. The target’s speed and PA are 0.23 arcsec/min and 302 deg respectively. The target’s S/N on the shifted and stacked image is 15.
Right: Comparing the retrieval capability of TESS (conventional method) vs SPECULOOS (conventional method) vs SPECULOOS using digital tracking. Owing to its larger aperture SPECULOOS allows to find objects ~10 times fainter than TESS. Leveraging the digital tracking techniques allows to reach objects 10 times fainter than with the traditional technique. Figures from Burdanov et al. 2022.