Martin Schlecker

Doctoral Student @ Max Planck Institute for Astronomy



Welcome to my homepage.

I am an astrophysicist working in the field of planet formation and evolution, both from a theoretical perspective and by observing exoplanet systems with state-of-the-art telescopes.

Since September 2017, I have been a PhD student at the Max Planck Institute for Astronomy in Heidelberg and a fellow of the IMPRS School for Astronomy and Cosmic Physics.

My work revolves around planet population synthesis and exoplanet demographics.


compositional links between
 warm super-Earths
 and cold Jupiters

Schlecker et al., 2020a, also check out the press release (available in English and German).

In our recent paper, we test what planet formation has to say about a peculiar trend that has been found in exoplanet demographics: around solar-type stars, inner super-Earths and outer giant planets tend to occur together. This challenges some established planet formation theories that predicted an anti-correlation of these planet types. Our synthetic population of 1000 multi-planet systems supports the observed trend, but with important caveats.

When we associate our initial conditions with the composition of the resulting planets, we see a quite interesting link: Depending on the initial solid mass, we either get isolated, icy super-Earths or rocky ones that have a cold Jupiter companion. This gives rise to the testable hypothesis that high-density inner super-Earths are proxies for cold Jupiters in the same system. A confirmation of this prediction would constrain central open questions in contemporary planet formation theory, ranging from efficiency of pebble accretion to planet migration behavior.

Simulation of the planet's orbit, photometric light curve, and radial velocity time series. The sizes of the bodies are not to scale but the orbit configuration is as we observe it, given our best-fit orbital elements. Animation created with the aid of the fantastic starry package (Luger et al., 2019).

A Highly Eccentric Warm Jupiter orbiting a solar-type star

Schlecker et al., accepted to The Astronomical Journal

The orbital parameters of warm Jupiters serve as a record of their formation history, providing constraints on formation scenarios for giant planets on close and intermediate orbits. In my new study with the WINE (Warm gIaNts with tEss) collaboration, we report the discovery of a new exoplanet that we detected in full frame images of TESS and followed up with ground-based photometry (CHAT and LCOGT) and radial velocity measurements (FEROS). We precisely constrain its mass to Mp= 1.94 +/- 00.1 Mj, and its radius to Rp = 1.24 +/- 0.15 Rj. It orbits a G-type star (Ms = 1.03 +/- 0.06 Msun, V = 12.1 mag) on one of the most eccentric orbits of all known warm giants. In fact, with a period of 15.17 d and e ≈ 0.57 its orbital parameters resemble those of the TESS spacecraft. This extreme dynamical state points to a past interaction with an additional, undetected massive companion. A tidal evolution analysis showed a large tidal dissipation timescale, suggesting that the planet is not a progenitor for a hot Jupiter caught during its high-eccentricity migration. This planet further represents an attractive opportunity to study the energy deposition and redistribution in the atmosphere of a warm Jupiter with high eccentricity.

Planet tracks of a simulated multi-planet system resembling TRAPPIST-1. As time evolves from left to right, this busy system undergoes quite a few changes. When some planets migrate inwards faster than others, they interact gravitationally and some of them merge. The innermost planets show rapid resonant migration. When the protoplanetary disk disperses at ~7 Gyr, a compact system of six planets remains. For comparison, we show the seven planets discovered in the TRAPPIST-1 system as dots in the same scale.

M-dwarf Population Synthesis

Burn, Schlecker et al., in prep.,
Schlecker, Burn et al., in prep.

Planet Population Synthesis is a holistic approach to study the conditions necessary for planet formation and evolution. It compares the properties of observed exoplanets, e.g. mass and orbital radius, to the ones obtained from planet formation simulations. This technique is particularly promising if one has access to an observational data set with a well-known detection bias that can be taken into account when comparing observations with theory.

We work on adapting our formation model to low-mass stars in order to compare it to surveys like CARMENES, which searches for Earth-mass planets around nearby M-dwarf stars. Such comparisons will improve our understanding of key processes such as the growth of planetesimals and their migration behavior. Stay tuned!

EDEN's global network of observatories. Our student group controls the Calar Alto 1.2m telescope.

Project EDEN

Gibbs, Bixel, Rackham, Apai, Schlecker et al. 2020

The ExoEarth Discovery and Exploration Network (EDEN) transit survey is a large-scale search for transiting habitable zone Earth-sized planets around nearby stars. In contrast to most ongoing and past surveys, the EDEN team utilizes large research telescopes (0.8 m–2.4 m), which allows for efficient probing of the habitable zones of late M-dwarf stars.

I am leading a team of 12 PhD students that observes with EDEN's workhorse, the Calar Alto 1.2 m telescope. As of fall 2020, we contributed already more than 150 full nights of observations. Being interested in planet demographics, I am also involved in EDEN's target selection and survey statistics.

My trajectory in science

Since 2017: PhD in Astronomy
Max Planck Institute for Astronomy

Currently, I am pursuing a PhD under supervision of Thomas Henning and Hubert Klahr at the Max Planck Institute for Astronomy.

2016–2017: Master's Thesis
European Southern Observatory

For my Master's project, I investigated irregular transit signatures in photometry of the Kepler space telescope.

2015: Internship
German Aerospace Center (DLR)

During my Master's, I took a semester off to help perform validation tests of DLR's HP3 heat flow probe. Currently, it is hammering itself into the Martian ground as a major payload of NASA's InSight mission.

2013: Bachelor's Thesis
Max Planck Institute for Extraterrestrial Physics

In my Bachelor's thesis, I characterized the optics of the X-Ray space telescope micro-ROSI.