Hi! I am an astrophysicist hunting for new exoplanets. Since 2018, I am a Torres Fellow at the Massachusetts Institute of Technology (MIT), working on small exoplanets, small stars and stellar flares with the Transiting Exoplanet Survey Satellite (TESS) team. Whenever I am not searching for new worlds, I enjoy travelling, the outdoors (scuba diving, rock climbing and hiking), and exploring our own Earth.

Expertise: Exoplanets, Stellar Flares, Cool Stars, Habitability

Skills: Bayesian Statistics, Machine Learning, Time Series Analysis

My PhD was obtained at the University of Cambridge, UK, where I worked in Professor Didier Queloz's group at the Exoplanet Research Centre. My research was focused on how we can distinguish between real exoplanets and stuff that looks like exoplanets, but is not (false positives). I worked with the Next Generation Transit Survey, a ground-based array of telescopes on the hunt for Neptune-sized exoplanets.

For my Master’s Thesis, I did something completely different: research in the biophysics lab of Professor George Shubeita at the University of Austin at Texas (Hook 'em Horns). I developed a mathematical model furthering our understanding of animal models of genetic diseases like Alzheimer's and Fragile X.

My physics undergraduate education was at the University of Würzburg, where I studied AGN mega-masers in the multi-wavelength group of Professor Matthias Kadler.

(Yellowstone. Credit: M. Günther)

How do stellar flares impact habitability?

Why care about flares? Because flares can impact habitability - they may erode exoplanets' atmospheres, but might also trigger the genesis of life. And all of this is especially important around M-dwarfs! To model flares, we use our public allesfitter code (Günther&Daylan, in prep.). It not only models exoplanets&binaries and red noise (with GPs), but also robustly selects the appropriate model for potentially complex flares via Bayesian evidence. Using Nested Sampling, we can compute the Bayes factors of diffferent models - pure noise, 1 flare, 2 flares, and so on. So what do we find? From the sample of ~25,000 TESS objects we find ~760 flaring stars, ~630 of which are M-dwarfs. Especially the mid M-dwarfs are `flary'. And one of the coolest (no pun intended) things: TESS explores so many bright early to late M-dwarfs! Of course, thanks to Kepler/K2/NGTS/MEarth/EVRYSCOPE and others we already learned some things about their flares - but TESS truly opens up new avenues here. Moreover, we find that fast rotating M-dwarfs are the most likely to flare, solidifying previous findings by other studies. And one of my personal favorites: the large amplitude flare on an M4.5 dwarf, raising the stellar brightness by a factor of 15.7! This goliath is even preceeded by a series of `warm-up' flares. Finally, we link all this flaring to prebiotic chemistry, coronal mass ejections, and ozone depletion. This figure contains a lot of info, and a detailed explanation is beyond this tweet - so if all this raised your interest, have a look at the paper :)

See Günther, M.N. et al., 2019a

Small exoplanets around small stars: TOI-270

The TOI-270 system is a true Disneyland for us exoplanet scientists. With three small exoplanets orbiting a red dwarf star, TOI-270 is a prime example of the type of system the Transiting Exoplanet Survey Satellite (TESS) set out to discover, and will soon provide a lot of puzzle pieces we are currently missing. The star TOI-270, only 40% the size and mass of our Sun, has three planets in orbit: one slightly bigger than Earth and likely rocky, and two double the size of Earth and probably of a similar composition as Neptune - rocky cores covered by a thick gas atmosphere. Being one of the nearest and brightest such systems, TOI-270 is a true Disneyland for exoplanet science. It is relatively easy to observe and offers something for every research area, from formation and dynamics to atmosphere and habitability studies. The unique, open spirit of the TESS community made this discovery possible, and various follow-up efforts are already in progress. So stay tuned for more exciting TOI-270 news in the future. Go TESS!

Read more in our Nature Astronomy Blog, the New York Times, or The Economist.

See Günther, M.N. et al., 2019b,

Other research projects

Click here to read more about some of my other studies:

• Unmasking the hidden NGTS-3Ab (see Günther, M.N. et al., 2018)
• Identifying false positives by measuring stellar light to 0.00025 image pixel (see Günther, M.N. et al., 2017b)
• Optimizing the yield of transit surveys (see Günther, M.N. et al., 2017a)

(Artist illustration of TOI-270. Credit: Sci-News.com)

The Transiting Exoplanet Survey Satellite (TESS)

The Transiting Exoplanet Survey Satellite (TESS) is set to discover thousands of new exoplanets. Launched in April 2018, TESS now monitors millions of stars for temporary drops in brightness, which are caused by planetary transits. It will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances - and maybe even Earth 2.0.

The TESS discovery of Pi Men c (some call it the first TESS planet): video, cnet, sciencenews, dailystar, sciencealert

The TESS discover of HD 21749 b and c (TESS' first Earth-sized planet): New York Times

The Next Generation Transit Survey (NGTS)

The Next Generation Transit Survey (NGTS) is an exoplanet hunter based in Paranal, Chile. With its 12 fully robotized 20 cm telescopes, NGTS covers a total field of view of almost 100 sq. deg. on the sky at once. The main goal of NGTS is to find transiting Neptunes that will be suitable for RV follow-up and mass measurements using current and future instruments such as HARPS and ESPRESSO.

(TESS. Credit: NASA's Goddard Space Flight Center)

2019

'Ask/Tell a Scientist' at the Science Festival in Cambridge, MA, USA: Enagaged in open discussions with the public about any scientific topic, from astronomy to biology.

2018

Volunteered for a month with marine biologists in Mozambique, studying and teaching about marine conservation - sprinkled with some astrophysics.

2017

Hosted a public evening on exoplanets in Burgkunstadt Germany, and gave a visiting tutorial for the high school's astrophysics course. Featured in the local German news (web1, web2) and on the school's website (web1, web2).

Tutored high-performing high-school students in physics and astronomy over multiple months, as part of 'The Brilliant Club' - a charitable programme focussed on low-participation neighbourhoods (web).

2016

Bringing exoplanet science to 8-12 year old pupils in Barton Road and Milton Road Primary Schools. Thanks to the Cambridge Science Festival Roadshow for this fantastic programme (leaflet).

2015

Initiated a public evening on exoplanets hosted at my former high school, Gymnasium Burgkunstadt, in Germany. The evening was featured in articles in the Obermain Tagblatt (web) and on the school's website (web).

(Outreach event, Germany. Credit: OT/Adriane Lochner )