Ruprecht-Karls-Universität Heidelberg

Dr. Yiannis Tsapras


Astronomisches Rechen-Institut



Office
Neubau, Room N.2-20

Postal Address
Zentrum für Astronomie der Universität Heidelberg
Astronomisches Rechen-Institut
Mönchhofstr. 12-14
69120 Heidelberg






Research interests
My primary research interests lie in the field of exoplanet science and I am involved in projects that use the complementary techniques of microlensing, radial velocity and transits to search for planets orbiting distant stars. Besides exoplanets, I work on robotic astronomy and participate in studies of variable stars.



58.
11/2024
Maskoliūnas, M.; Wyrzykowski, Ł. et al. (inc. Wambsganss, J.; Tsapras, Y.; Hundertmark, M.; Heidt, J.; Kaczmarek, Z.)
Lens Mass Estimate in the Galactic Disk Extreme Parallax Microlensing Event Gaia19dke
AcA 74, 77(2024)

57.
10/2024
Liebing, F.; Jeffers, S. V. et al. (inc. Tsapras, Y.; Quirrenbach, A.)
RedDots: Limits on habitable and undetected planets orbiting nearby stars GJ 832, GJ 674, and Ross 128
A&A 690, A234(2024)

56.
8/2024
Wu, Zexuan; Dong, Subo et al. (inc. Wambsganss, J.; Hundertmark, M.; Tsapras, Y.)
Gaia22dkvLb: A Microlensing Planet Potentially Accessible to Radial-velocity Characterization
AJ 168, 62(2024)

55.
7/2024
Han, Cheongho; Bond, Ian A. et al. (inc. Wambsganss, Joachim; Hundertmark, Markus; Tsapras, Yiannis)
Four microlensing giant planets detected through signals produced by minor-image perturbations
A&A 687, A225(2024)

54.
7/2024
Bachelet, E.; Rota, P. et al. (inc. Wambsganss, J.; Hundertmark, M.; Tsapras, Y.)
A Close Binary Lens Revealed by the Microlensing Event Gaia20bof
AJ 168, 9(2024)

53.
6/2024
Rota, P.; Bozza, V. et al. (inc. Wambsganss, J.; Tsapras, Y.; Hundertmark, M.)
Gaia21blx: Complete resolution of a binary microlensing event in the Galactic disk
A&A 686, A173(2024)

52.
6/2024
Street, R. A.; Bachelet, E. et al. (inc. Wambsganss, J.; Hundertmark, M. P. G.; Tsapras, Y.)
ROME/REA: Three-year, Tri-color Timeseries Photometry of the Galactic Bulge
PASP 136, f4501(2024)

51.
10/2023
Hambleton, Kelly M.; Bianco, Federica B. et al. (inc. Tsapras, Yiannis; Hundertmark, Markus)
Rubin Observatory LSST Transients and Variable Stars Roadmap
PASP 135, j5002(2023)

50.
7/2023
Street, R. A.; Li, X. et al. (inc. Hundertmark, M. P. G.; Tsapras, Y.)
LSST Survey Strategy in the Galactic Plane and Magellanic Clouds
ApJS 267, 15(2023)

49.
4/2023
Olmschenk, Greg; Bennett, David P. et al. (inc. Wambsganss, Joachim; Tsapras, Y.; Hundertmark, Markus)
MOA-2020-BLG-208Lb: Cool Sub-Saturn-mass Planet within Predicted Desert
AJ 165, 175(2023)

48.
9/2022
Bachelet, E.; Tsapras, Y. et al. (inc. Wambsganss, J.; Hundertmark, M. P. G.)
MOA-2019-BLG-008Lb: A New Microlensing Detection of an Object at the Planet/Brown Dwarf Boundary
AJ 164, 75(2022)

47.
8/2022
Gorrini, P.; Astudillo-Defru, N. et al. (inc. Tsapras, Y.)
Detailed stellar activity analysis and modelling of GJ 832. Reassessment of the putative habitable zone planet GJ 832c
A&A 664, A64(2022)

46.
8/2022
Zang, Weicheng; Shvartzvald, Yossi et al. (inc. Tsapras, Yiannis; Hundertmark, Markus P. G.)
OGLE-2018-BLG-0799Lb: a q 2.7 × 10-3 planet with Spitzer parallax
MNRAS 514, 5952(2022)

45.
7/2022
Herald, A.; Udalski, A. et al. (inc. Tsapras, Y.; Hundertmark, M.; Ranc, C.)
Precision measurement of a brown dwarf mass in a binary system in the microlensing event. OGLE-2019-BLG-0033/MOA-2019-BLG-035
A&A 663, A100(2022)

44.
7/2022
Sahu, Kailash C.; Anderson, Jay et al. (inc. Tsapras, Yiannis; Wambsganss, Joachim; Hundertmark, Markus; Ranc, Clément)
An Isolated Stellar-mass Black Hole Detected through Astrometric Microlensing
ApJ 933, 83(2022)

43.
6/2022
Kruszyńska, K.; Wyrzykowski, Ł. et al. (inc. Tsapras, Y.; Hundertmark, M.)
Lens parameters for Gaia18cbf - a long gravitational microlensing event in the Galactic plane
A&A 662, A59(2022)

42.
1/2022
Cassan, Arnaud; Ranc, Clément et al. (inc. Wambsganss, Joachim; Tsapras, Yiannis; Hundertmark, Markus)
Microlensing mass measurement from images of rotating gravitational arcs
NatAs 6, 121(2022)

41.
1/2022
Rybicki, K. A.; Wyrzykowski, Ł. et al. (inc. Hundertmark, M.; Tsapras, Y.)
Single-lens mass measurement in the high-magnification microlensing event Gaia19bld located in the Galactic disc
A&A 657, A18(2022)

40.
1/2022
Bachelet, E.; Zieliński, P. et al. (inc. Hundertmark, M.; Tsapras, Y.)
A spectroscopic follow-up for Gaia19bld
A&A 657, A17(2022)

39.
11/2021
Yee, Jennifer C.; Zang, Weicheng et al. (inc. Tsapras, Yiannis; Hundertmark, Markus P. G.)
OGLE-2019-BLG-0960 Lb: the Smallest Microlensing Planet
AJ 162, 180(2021)

38.
8/2021
Kondo, Iona; Yee, Jennifer C. et al. (inc. Wambsganss, J.; Tsapras, Y.; Hundertmark, Markus P. G.)
OGLE-2018-BLG-1185b: A Low-mass Microlensing Planet Orbiting a Low-mass Dwarf
AJ 162, 77(2021)

37.
7/2021
Hitchcock, James A.; Hundertmark, Markus et al. (inc. Tsapras, Yiannis)
PyTorchDIA: a flexible, GPU-accelerated numerical approach to Difference Image Analysis
MNRAS 504, 3561(2021)

36.
8/2020
Szegedi-Elek, E.; Ábrahám, P. et al. (inc. Tsapras, Y.; Hundertmark, M.)
Gaia 18dvy: A New FUor in the Cygnus OB3 Association
ApJ 899, 130(2020)

35.
8/2020
Hirao, Yuki; Bennett, David P. et al. (inc. Tsapras, Yiannis; Hundertmark, Markus)
OGLE-2017-BLG-0406: Spitzer Microlens Parallax Reveals Saturn-mass Planet Orbiting M-dwarf Host in the Inner Galactic Disk
AJ 160, 74(2020)

34.
3/2020
Zang, Weicheng; Shvartzvald, Yossi et al. (inc. Hundertmark, Markus; Tsapras, Yiannis)
Spitzer Microlensing Parallax Reveals Two Isolated Stars in the Galactic Bulge
ApJ 891, 3(2020)

33.
2/2020
Miyazaki, Shota; Sumi, Takahiro et al. (inc. Wambsganss, J.; Schmidt, R.; Hundertmark, M. P. G.; Tsapras, Y.)
OGLE-2013-BLG-0911Lb: A Secondary on the Brown-dwarf Planet Boundary around an M Dwarf
AJ 159, 76(2020)

32.
1/2020
Wyrzykowski, Ł.; Mróz, P. et al. (inc. Wambsganss, J.; Tsapras, Y.; Schmidt, R.; Ment, K.; Hundertmark, M.)
Full orbital solution for the binary system in the northern Galactic disc microlensing event Gaia16aye
A&A 633, A98(2020)

31.
12/2019
Tsapras, Yiannis; Street, R. A. et al. (inc. Wambsganss, J.; Hundertmark, M.)
ROME/REA: A Gravitational Microlensing Search for Exoplanets Beyond the Snow Line on a Global Network of Robotic Telescopes
PASP 131, l4401(2019)

30.
11/2019
Nagakane, M.; Lee, Chien-Hsiu et al. (inc. Wambsganss, J.; Tsapras, Y.; Schmidt, R.; Hundertmark, M.)
OGLE-2015-BLG-1649Lb: A Gas Giant Planet around a Low-mass Dwarf
AJ 158, 212(2019)

29.
11/2019
Fukui, A.; Suzuki, D. et al. (inc. Hundertmark, M.; Tsapras, Y.)
Kojima-1Lb Is a Mildly Cold Neptune around the Brightest Microlensing Host Star
AJ 158, 206(2019)

28.
9/2019
Li, S. -S.; Zang, W. et al. (inc. Hundertmark, M.; Tsapras, Y.)
OGLE-2017-BLG-1186: first application of asteroseismology and Gaussian processes to microlensing
MNRAS 488, 3308(2019)

27.
8/2019
Tsapras, Y.; Cassan, A. et al. (inc. Wambsganss, J.; Schmidt, R.; Euteneuer, E.; Hundertmark, M.)
An analysis of binary microlensing event OGLE-2015-BLG-0060
MNRAS 487, 4603(2019)

26.
6/2019
Street, R. A.; Bachelet, E. et al. (inc. Wambsganss, J.; Hundertmark, M. P. G.; Tsapras, Y.)
OGLE-2018-BLG-0022: A Nearby M-dwarf Binary
AJ 157, 215(2019)

25.
4/2019
Dominik, M.; Bachelet, E. et al. (inc. Wambsganss, J.; Tsapras, Y.; Schmidt, R.; Hundertmark, M.)
OGLE-2014-BLG-1186: gravitational microlensing providing evidence for a planet orbiting the foreground star or for a close binary source?
MNRAS 484, 5608(2019)

24.
3/2019
Shvartzvald, Yossi; Yee, Jennifer C. et al. (inc. Tsapras, Yiannis)
Spitzer  Microlensing Parallax for OGLE-2017-BLG-0896 Reveals a Counter-rotating Low-mass Brown Dwarf
AJ 157, 106(2019)

23.
1/2019
Bachelet, E.; Bozza, V. et al. (inc. Wambsganss, J.; Tsapras, Y.; Schmidt, R.; Hundertmark, M.)
First Assessment of the Binary Lens OGLE-2015-BLG-0232
ApJ 870, 11(2019)

22.
11/2018
Ribas, I.; Tuomi, M. et al. (inc. Tsapras, Y.; Seifert, W.; Reffert, S.; Kaminski, A.; Quirrenbach, A.)
A candidate super-Earth planet orbiting near the snow line of Barnard's star
Natur 563, 365(2018)

21.
1/2018
Hundertmark, M.; Street, R. A. et al. (inc. Ment, K.; Wambsganss, J.; Schmidt, R. W.; Tsapras, Y.)
RoboTAP: Target priorities for robotic microlensing observations
A&A 609, A55(2018)

20.
1/2018
Ryu, Y. -H.; Yee, J. C. et al. (inc. Ment, S. K.; Wambsganss, J.; Schmidt, R.; Hundertmark, M.; Tsapras, Y.)
OGLE-2016-BLG-1190Lb: The First Spitzer Bulge Planet Lies Near the Planet/Brown-dwarf Boundary
AJ 155, 40(2018)

19.
8/2017
Wang, Tianshu; Zhu, Wei et al. (inc. Schmidt, R.; Wambsganss, J.; Hundertmark, M.; Tsapras, Y.)
Ground-based Parallax Confirmed by Spitzer: Binary Microlensing Event MOA-2015-BLG-020
ApJ 845, 129(2017)

18.
7/2017
Koshimoto, N.; Shvartzvald, Y. et al. (inc. Tsapras, Y.; Hundertmark, M.)
MOA-2016-BLG-227Lb: A Massive Planet Characterized by Combining Light-curve Analysis and Keck AO Imaging
AJ 154, 3(2017)

17.
4/2017
Rattenbury, N. J.; Bennett, D. P. et al. (inc. Schmidt, R.; Wambsganss, J.; Hundertmark, M.; Giannini, E.; Diehl, C.; Tsapras, Y.)
Faint-source-star planetary microlensing: the discovery of the cold gas-giant planet OGLE-2014-BLG-0676Lb
MNRAS 466, 2710(2017)

16.
2/2017
Tsapras, Y.; Arellano Ferro, A. et al.
Variable stars in the bulge globular cluster NGC 6401
MNRAS 465, 2489(2017)

15.
12/2016
Henderson, Calen B.; Poleski, Radosław et al. (inc. Wambsganss, J.; Tsapras, Y.; Schmidt, R.)
Campaign 9 of the K2 Mission: Observational Parameters, Scientific Drivers, and Community Involvement for a Simultaneous Space- and Ground-based Microlensing Survey
PASP 128, l4401(2016)

14.
11/2016
Bennett, D. P.; Rhie, S. H. et al. (inc. Zub, M.; Wambsganss, J.; Tsapras, Y.)
The First Circumbinary Planet Found by Microlensing: OGLE-2007-BLG-349L(AB)c
AJ 152, 125(2016)

13.
11/2016
Bhattacharya, A.; Bennett, D. P. et al. (inc. Wambsganss, J.; Schmidt, R.; Tsapras, Y.)
Discovery of a Gas Giant Planet in Microlensing Event OGLE-2014-BLG-1760
AJ 152, 140(2016)

12.
11/2016
Shvartzvald, Y.; Li, Z. et al. (inc. Wambsganss, J.; Schmidt, R.; Tsapras, Y.)
The First Simultaneous Microlensing Observations by Two Space Telescopes: Spitzer and Swift Reveal a Brown Dwarf in Event OGLE-2015-BLG-1319
ApJ 831, 183(2016)

11.
9/2016
Han, C.; Udalski, A. et al. (inc. Wambsganss, J.; Schmidt, R.; Figuera Jaimes, R.; Tsapras, Y.)
OGLE-2015-BLG-0479LA,B: Binary Gravitational Microlens Characterized by Simultaneous Ground-based and Space-based Observations
ApJ 828, 53(2016)

10.
8/2016
Anglada-Escudé, Guillem; Amado, Pedro J. et al. (inc. Tsapras, Yiannis)
A terrestrial planet candidate in a temperate orbit around Proxima Centauri
Natur 536, 437(2016)

9.
7/2016
Zhu, Wei; Calchi Novati, S. et al. (inc. Wambsganss, J.; Schmidt, R.; Tsapras, Y.)
Mass Measurements of Isolated Objects from Space-based Microlensing
ApJ 825, 60(2016)

8.
5/2016
Poleski, Radosław; Zhu, Wei et al. (inc. Schmidt, R.; Wambsganss, J.; Tsapras, Y.)
The Spitzer Microlensing Program as a Probe for Globular Cluster Planets: Analysis of OGLE-2015-BLG-0448
ApJ 823, 63(2016)

7.
4/2016
Tsapras, Y.; Hundertmark, M. et al.
The OGLE-III planet detection efficiency from six years of microlensing observations (2003-2008)
MNRAS 457, 1320(2016)

6.
3/2016
Street, R. A.; Udalski, A. et al. (inc. Schmidt, R. ; Wambsganß, J.; Tsapras, Y.)
Spitzer Parallax of OGLE-2015-BLG-0966: A Cold Neptune in the Galactic Disk
ApJ 819, 93 (2016)

5.
12/2015
Shvartzvald, Y.; Udalski, A. et al. (inc. Schmidt, R.; Wambsganss, J.; Tsapras, Y.)
Spitzer Microlens Measurement of a Massive Remnant in a Well-separated Binary
ApJ 814, 111(2015)

4.
8/2015
Ranc, C.; Cassan, A. et al. (inc. Zub, M.; Wambsganss, J.; Tsapras, Y.)
MOA-2007-BLG-197: Exploring the brown dwarf desert
A&A 580, A125(2015)

3.
8/2015
Fukui, A.; Gould, A. et al. (inc. Tsapras, Y.)
OGLE-2012-BLG-0563Lb: A Saturn-mass Planet around an M Dwarf with the Mass Constrained by Subaru AO Imaging
ApJ 809, 74(2015)

2.
12/2009
Batista, V.; Dong, S. et al. (inc. Williams, A.; Tsapras, Y.; Cassan, A.)
Mass measurement of a single unseen star and planetary detection efficiency for OGLE 2007-BLG-050
A&A 508, 467(2009)

1.
11/2009
Han, C.; Hwang, K. -H. et al. (inc. Tsapras, Y.; Burgdorf, M.)
Interpretation of Strong Short-Term Central Perturbations in the Light Curves of Moderate-Magnification Microlensing Events
ApJ 705, 1116(2009)

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