Planet Hunting

Exoplanets - planets around star other than the sun - are nowadays being found by the dozens and start to be characterized in detail now.

Direct Imaging

The CONICA Spectral Differential Imager (SDI) upgrade is a 4-channel imager, observing simultaneously in three distinct wavelength bands between 1.56 micron and 1.64 micron. CONICA SDI is taylored towards the detection of T- and Y-class companions to nearby young stars, and is capable of reaching brightness contrasts of δH = 10.36 mag for a T6 object at 5-σ in 10-25 minutes at a separation of 0.5" from the target star.

The NaCo survey for giant planets around nearby stars is a large GTO project to directly image extra-solar planets in L-band on a VLT unit telescope (UT) at ESO's Paranal observatory. The survey starts in December 2015 and is carried out jointly by the three partners of the former PRIMA-DDL consortium: MPIA, LSW, and University of Geneva. The main scientific aim of this survey is the revelation and characterization of the theoretically hypothesized but largely unknown wide-separation (>10au) planet population that may originate from a mix of in-situ formation and early dynamical evolution. Although the survey will be partially overlapping with other state-of-the-art large exoplanet imaging surveys, like with SPHERE or GPI, it will cover a different parameter range by exploiting the L-band sensitivity of NaCo to lower-mass and older planets.

SEEDS (The "Strategic Exploration of Exoplanets and Disks with Subaru) is a Subaru-HiCIAO-AO188 direct imaging survey, searching for giant planets (1 MJ < mass <~13 MJ) and protoplanetary/debris disks mainly around ~500 nearby solar-type or more massive young stars. The ages of our exoplanet target stars span ~1-10 Myr for YSOs in nearest star forming regions, through ~100-500 Myr old stars in nearby open clusters, to ~1 Gyr old nearby stars. Proposed to be conducted within 5 years, the survey is now at its half-way point and a number of confirmed detections have been published.

LEECH (LBTI Exozodi Exoplanet Common Hunt) is a large programme taking advantage of LBT's unique adaptive optics systems and image quality in the 3 to 5 micron range. The survey, which is carried out in parallel with NASA's exozodi key science program, is running from 2013 to 2016. The goals of LEECH are to (1) discover new exoplanets, (2) characterize the atmospheres of newly discovered planets, (3) characterize the architectures of nearby planetary systems, and (4) establish meaningful constraints on the prevalence of wide-separation exoplanets. Compared to other direct imaging surveys, planets discovered by LEECH will be older and around more nearby stars. Finding older planets will enable studies of the evolution of exoplanet atmospheres.

SPHERE is a project to directly image extra-solar planets on a VLT unit telescope (UT) on ESO's Paranal observatory. This ambitious goal will be achieved by constructing an instrument that offers a unique combination of eXtreme Adaptive Optics (XAO), coronography, and three differential imaging-capable focal plane instruments. The instrument will be operated in survey mode and spent about 500 nights searching the sky for nearby exo-planets of Jupiter-size and at ages ranging from a few million years to some gigayears.

To date, the vast majority of thoroughly characterized exoplanetary systems (i.e., those for which we have precise masses and radii, most of which transit their stars) are part of the so-called "hot Jupiter" family --- exoplanets in short-period orbits (and thus, large equilibrium temperatures) whose detection and characterization is relatively easy to perform with current technology. In contrast, only a handful of transiting giant exoplanets in longer-period orbits (> 10 days and, thus, "warmer" in terms of their equilibrium temperatures) have been discovered and thoroughly characterized, as their longer periods makes them hard to detect with ground-based observatories. These so-called "warm" giant exoplanets, are in turn key to our understanding of the formation and evolution of giant exoplanets, including the giant planets in our own Solar System. It is in this context that the *W*arm G*I*a*N*ts with T*E*SS (WINE) collaboration was formed --- a multi-institutional effort involving researchers from the Max-Planck Institut fuer Astronomy (MPIA) in Germany, the Pontificia Universidad Católica de Chile (PUC) and Universidad Adolfo Ibañez (UAI) in Chile and the Space Telescope Science Institute (STScI) in the United States --- which is aimed at the detection and characterization of these warm giant exoplanets using data from the Transiting Exoplanet Survey Satellite (TESS) mission. The main goal of the project is to perform a systematic study of warm giant exoplanets starting with their detection and follow-up using ground-based facilities, to the understanding of how these systems form and what they are made of. The project is currently led by Dr. Rafael Brahm (PUC), Dr. Néstor Espinoza (STScI), Prof. Dr. Thomas Henning (MPIA) and Prof. Dr. Andrés Jordán (UAI).

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