PTYS/LPL Faculty

Daniel Apai

Associate Professor
Astrobiology, Exoplanetary systems, Planet formation
Ph.D., 2004, University of Heidelberg

Steward N208B

Years with LPL: 2011 to present


Dr. Apai’s research focuses on the formation and properties of exoplanetary systems, through direct observations of protoplanetary and debris disks and giant exoplanets. He is particularly interested in the formation of habitable planets and the characterization of exoplanetary atmospheres, including the search for biomarkers.

Dr. Apai’s group studies exoplanets via high-contrast imaging and by observing exoplanetary transits and eclipses. High-contrast imaging allows the exploration of the exoplanet population in the outer planetary systems, leading to the discovery and characterization of giant planets and constraints on their frequency. Planetary eclipses, on the other hand, enable the study of heavily irradiated exoplanets with atmospheres as hot as red dwarf stars.

Studies of planetary atmospheres provide only limited information on the bulk composition and geophysics of planets: detailed understanding of the physics of exoplanets also requires an understanding of their formation. Dr. Apai has worked on establishing a consistent framework for planet formation in the Solar System and around other stars by reconciling the meteoritic and Solar System evidence with astronomical observations. He also carried out detailed studies that demonstrated that the initial and boundary conditions of planet formation are stellar mass-dependent, arguing for different disk evolution around the much more common low-mass stars.

Read Dr. Apai's blog on exoplanet exploration and astrobiology here.

Current Grants

  • ACCESS - A transmission spectroscopy survey of exoplanet atmospheres with the goal to compile a comprehensive spectral library of exoplanets, from hot jupiters to super-earths.
  • Scorpion Survey - A 100-star VLT extreme adaptive optics high-contrast imaging survey for giant exoplanets.
  • Earths in Other Solar Systems - A large interdisciplinary NASA Nexus for Exoplanet System Science project to explore how habitable zone earth-sized planets acquire their volatiles and organics required to be habitable. This 5-year, $5.7M interdisciplinary project includes 17 graduate students and postdocs and 20 senior investigators.
  • Cloud Atlas - A Large Treasury program with the Hubble Space Telescope to determine how cloud deck properties in brown dwarfs and exoplanets depend on surface gravity and temperature.
  • Extrasolar Storms - The Physics and Chemistry of Evolving Cloud Structures in Brown Dwarf Atmospheres: Spitzer Exploration Science Program (PI Apai)

Current PTYS Graduate Students

Student Collaborations/Advising

Former Students

  • Davin Flateau, 2015 (M.S.)
  • Jake Ryan Hanson, 2014, University of Arizona
  • Judit Szulagyi, 2010-2011, Space Telescope Science Institute and Eotvos Lorand University
  • Laszlo Szucs, 2009-2011, Space Telescope Science Institute and University of Szeged
  • Veselin Kostov, 2009, Johns Hopkins University
  • Justin Rogers, 2008-2012, Johns Hopkins University
  • Emily Hardegree-Ullman, 2006-2007, University of Arizona
  • Yancey Sechrest, 2005-2006, University of Arizona
  • Emily E. Berkson (UA Astronomy)
  • William Nolan (UA CAMPARE)

Current Postdocs

  • Elena Manjavacas
  • Jonathan Rees

Former Postdocs

  • Esther Buenzli
  • Theodora Karalidi
  • Gijs Mulders
  • Hao Yang


Complete publications list available from: NASA ADS Author search: Daniel Apai

Refereed publications (NASA ADS): Calendar Year 2016 through July 2018

Mulders, G. D., Pascucci, I., Apai, D., Ciesla, F. J.  The Exoplanet Population Observation Simulator. I. The Inner Edges of Planetary Systems 2018AJ....156...24M

Burnam-Fink, M., Desch, S. J., Scalice, D., Davis, H., Huff, C. J., Apai, D.  Impact of the Arizona NExSS Winter School on Astrobiology Knowledge and Attitudes 2018AsBio..18..365B

Zhou, Y., Apai, D., Metchev, S., Lew, B. W. P., Schneider, G., Marley, M. S., Karalidi, T., Manjavacas, E., Bedin, L. R., Cowan, N. B., Miles-Páez, P. A., Lowrance, P. J., Radigan, J., Burgasser, A. J.  Cloud Atlas: Rotational Modulations in the L/T Transition Brown Dwarf Companion HN Peg B 2018AJ....155..132Z

Wagner, K., Dong, R., Sheehan, P., Apai, D., Kasper, M., McClure, M., Morzinski, K. M., Close, L., Males, J., Hinz, P., Quanz, S. P., Fung, J.  The Orbit of the Companion to HD 100453A: Binary-driven Spiral Arms in a Protoplanetary Disk 2018ApJ...854..130W

Libralato, M., Bellini, A., Bedin, L. R., Moreno D., E., Fernández-Trincado, J. G., Pichardo, B., van der Marel, R. P., Anderson, J., Apai, D., Burgasser, A. J., Fabiola Marino, A., Milone, A. P., Rees, J. M., Watkins, L. L.  The HST Large Programme on ω Centauri. III. Absolute Proper Motion 2018ApJ...854...45L

Rackham, B. V., Apai, D., Giampapa, M. S.  The Transit Light Source Effect: False Spectral Features and Incorrect Densities for M-dwarf Transiting Planets 2018ApJ...853..122R

Bellini, A., Libralato, M., Bedin, L. R., Milone, A. P., van der Marel, R. P., Anderson, J., Apai, D., Burgasser, A. J., Marino, A. F., Rees, J. M.  The HST Large Programme on ω Centauri. II. Internal Kinematics 2018ApJ...853...86B

Manjavacas, E., Apai, D., Zhou, Y., Karalidi, T., Lew, B. W. P., Schneider, G., Cowan, N., Metchev, S., Miles-Páez, P. A., Burgasser, A. J., Radigan, J., Bedin, L. R., Lowrance, P. J., Marley, M. S.  Cloud Atlas: Discovery of Rotational Spectral Modulations in a Low-mass, L-type Brown Dwarf Companion to a Star 2018AJ....155...11M

Bedin, L. R., Pourbaix, D., Apai, D., Burgasser, A. J., Buenzli, E., Boffin, H. M. J., Libralato, M.  Hubble Space Telescope astrometry of the closest brown dwarf binary system - I. Overview and improved orbit 2017MNRAS.470.1140B

Apai, D., Karalidi, T., Marley, M. S., Yang, H., Flateau, D., Metchev, S., Cowan, N. B., Buenzli, E., Burgasser, A. J., Radigan, J., Artigau, E., Lowrance, P.  Zones, spots, and planetary-scale waves beating in brown dwarf atmospheres 2017Sci...357..683A

Long, F., Herczeg, G. J., Pascucci, I., Drabek-Maunder, E., Mohanty, S., Testi, L., Apai, D., Hendler, N., Henning, T., Manara, C. F., Mulders, G. D.  An ALMA Survey of CO Isotopologue Emission from Protoplanetary Disks in Chamaeleon I 2017ApJ...844...99L

Milone, A. P., Marino, A. F., Bedin, L. R., Anderson, J., Apai, D., Bellini, A., Bergeron, P., Burgasser, A. J., Dotter, A., Rees, J. M.  The HST large programme on ω Centauri – I. Multiple stellar populations at the bottom of the main sequence probed in NIR–Optical 2017MNRAS.469..800M

Smart, R. L., Apai, D., Kirkpatrick, J. D., Leggett, S. K., Marocco, F., Morrison, J. E., Jones, H. R. A., Pinfield, D., Tremblin, P., Amundsen, D. S.  Parallaxes and infrared photometry of three Y0 dwarfs 2017MNRAS.468.3764S

Ricci, L., Cazzoletti, P., Czekala, I., Andrews, S. M., Wilner, D., Szűcs, L., Lodato, G., Testi, L., Pascucci, I., Mohanty, S., Apai, D., Carpenter, J. M., Bowler, B. P.  ALMA Observations of the Young Substellar Binary System 2M1207 2017AJ....154...24R

Zhou, Y., Apai, D., Lew, B. W. P., Schneider, G.  A Physical Model-based Correction for Charge Traps in the Hubble Space Telescope’s Wide Field Camera 3 Near-IR Detector and Its Applications to Transiting Exoplanets and Brown Dwarfs 2017AJ....153..243Z

Miles-Páez, P. A., Metchev, S. A., Heinze, A., Apai, D.  Weather on Other Worlds. IV. Hα Emission and Photometric Variability Are Not Correlated in L0–T8 Dwarfs 2017ApJ...840...83M

Fang, M., Kim, J. S., Pascucci, I., Apai, D., Zhang, L., Sicilia-Aguilar, A., Alonso-Martínez, M., Eiroa, C., Wang, H. V NGC 1980 Is Not a Foreground Population of Orion: Spectroscopic Survey of Young Stars with Low Extinction in Orion A 2017AJ....153..188F

Bixel, A., Apai, D. V Probabilistic Constraints on the Mass and Composition of Proxima b 2017ApJ...836L..31B

Rackham, B., Espinoza, N., Apai, D., López-Morales, M., Jordán, A., Osip, D. J., Lewis, N. K., Rodler, F., Fraine, J. D., Morley, C. V., Fortney, J. J.  ACCESS I: An Optical Transmission Spectrum of GJ 1214b Reveals a Heterogeneous Stellar Photosphere 2017ApJ...834..151R

Benisty, M., Stolker, T., Pohl, A., de Boer, J., Lesur, G., Dominik, C., Dullemond, C. P., Langlois, M., Min, M., Wagner, K., Henning, T., Juhasz, A., Pinilla, P., Facchini, S., Apai, D., van Boekel, R., Garufi, A., Ginski, C., Ménard, F., Pinte, C., Quanz, S. P., Zurlo, A., Boccaletti, A., Bonnefoy, M., Beuzit, J. L., Chauvin, G., Cudel, M., Desidera, S., Feldt, M., Fontanive, C., Gratton, R., Kasper, M., Lagrange, A.-M., LeCoroller, H., Mouillet, D., Mesa, D., Sissa, E., Vigan, A., Antichi, J., Buey, T., Fusco, T., Gisler, D., Llored, M., Magnard, Y., Moeller-Nilsson, O., Pragt, J., Roelfsema, R., Sauvage, J.-F., Wildi, F.  Shadows and spirals in the protoplanetary disk HD 100453 2017A&A...597A..42B

Fang, M., Kim, J. S., Pascucci, I., Apai, D., Manara, C. F.  A Candidate Planetary-mass Object with a Photoevaporating Disk in Orion 2016ApJ...833L..16F

Mulders, G. D., Pascucci, I., Apai, D., Frasca, A., Molenda-Żakowicz, J.  A Super-solar Metallicity for Stars with Hot Rocky Exoplanets 2016AJ....152..187M

Pascucci, I., Testi, L., Herczeg, G. J., Long, F., Manara, C. F., Hendler, N., Mulders, G. D., Krijt, S., Ciesla, F., Henning, T., Mohanty, S., Drabek-Maunder, E., Apai, D., Szűcs, L., Sacco, G., Olofsson, J.  A Steeper than Linear Disk Mass-Stellar Mass Scaling Relation 2016ApJ...831..125P

Lew, B. W. P., Apai, D., Zhou, Y., Schneider, G., Burgasser, A. J., Karalidi, T., Yang, H., Marley, M. S., Cowan, N. B., Bedin, L. R., Metchev, S. A., Radigan, J., Lowrance, P. J.  Cloud Atlas: Discovery of Patchy Clouds and High-amplitude Rotational Modulations in a Young, Extremely Red L-type Brown Dwarf 2016ApJ...829L..32L

Hornbeck, J. B., Swearingen, J. R., Grady, C. A., Williger, G. M., Brown, A., Sitko, M. L., Wisniewski, J. P., Perrin, M. D., Lauroesch, J. T., Schneider, G., Apai, D., Brittain, S., Brown, J. M., Champney, E. H., Hamaguchi, K., Henning, T., Lynch, D. K., Petre, R., Russell, R. W., Walter, F. M., Woodgate, B.  Panchromatic Imaging of a Transitional Disk: The Disk of GM Aur in Optical and FUV Scattered Light 2016ApJ...829...65H

Wagner, K., Apai, D., Kasper, M., Kratter, K., McClure, M., Robberto, M., Beuzit, J.-L.  Direct imaging discovery of a Jovian exoplanet within a triple-star system 2016Sci...353..673W

Yang, H., Apai, D., Marley, M. S., Karalidi, T., Flateau, D., Showman, A. P., Metchev, S., Buenzli, E., Radigan, J., Artigau, É., Lowrance, P. J., Burgasser, A. J.  Extrasolar Storms: Pressure-dependent Changes in Light-curve Phase in Brown Dwarfs from Simultaneous HST and Spitzer Observations 2016ApJ...826....8Y

Karalidi, T., Apai, D., Marley, M. S., Buenzli, E.  Maps of Evolving Cloud Structures in Luhman 16AB from HST Time-resolved Spectroscopy 2016ApJ...825...90K

Kun, M., Wolf-Chase, G., Moór, A., Apai, D., Balog, Z., O'Linger-Luscusk, J., Moriarty-Schieven, G. H.  The Young Stellar Population of LYNDS 1340. An Infrared View 2016ApJS..224...22K

Apai, D., Kasper, M., Skemer, A., Hanson, J. R., Lagrange, A.-M., Biller, B. A., Bonnefoy, M., Buenzli, E., Vigan, A.  High-cadence, High-contrast Imaging for Exoplanet Mapping: Observations of the HR 8799 Planets with VLT/SPHERE Satellite-spot-corrected Relative Photometry 2016ApJ...820...40A

Zurlo, A., Vigan, A., Galicher, R., Maire, A.-L., Mesa, D., Gratton, R., Chauvin, G., Kasper, M., Moutou, C., Bonnefoy, M., Desidera, S., Abe, L., Apai, D., Baruffolo, A., Baudoz, P., Baudrand, J., Beuzit, J.-L., Blancard, P., Boccaletti, A., Cantalloube, F., Carle, M., Cascone, E., Charton, J., Claudi, R. U., Costille, A., de Caprio, V., Dohlen, K., Dominik, C., Fantinel, D., Feautrier, P., Feldt, M., Fusco, T., Gigan, P., Girard, J. H., Gisler, D., Gluck, L., Gry, C., Henning, T., Hugot, E., Janson, M., Jaquet, M., Lagrange, A.-M., Langlois, M., Llored, M., Madec, F., Magnard, Y., Martinez, P., Maurel, D., Mawet, D., Meyer, M. R., Milli, J., Moeller-Nilsson, O., Mouillet, D., Origné, A., Pavlov, A., Petit, C., Puget, P., Quanz, S. P., Rabou, P., Ramos, J., Rousset, G., Roux, A., Salasnich, B., Salter, G., Sauvage, J.-F., Schmid, H. M., Soenke, C., Stadler, E., Suarez, M., Turatto, M., Udry, S., Vakili, F., Wahhaj, Z., Wildi, F., Antichi, J.  First light of the VLT planet finder SPHERE. III. New spectrophotometry and astrometry of the HR 8799 exoplanetary system 2016A&A...587A..57Z

Zhou, Y., Apai, D., Schneider, G. H., Marley, M. S., Showman, A. P.  Discovery of Rotational Modulations in the Planetary-mass Companion 2M1207b: Intermediate Rotation Period and Heterogeneous Clouds in a Low Gravity Atmosphere 2016ApJ...818..176Z

Skemer, A. J., Morley, C. V., Zimmerman, N. T., Skrutskie, M. F., Leisenring, J., Buenzli, E., Bonnefoy, M., Bailey, V., Hinz, P., Defrére, D., Esposito, S., Apai, D., Biller, B., Brandner, W., Close, L., Crepp, J. R., De Rosa, R. J., Desidera, S., Eisner, J., Fortney, J., Freedman, R., Henning, T., Hofmann, K.-H., Kopytova, T., Lupu, R., Maire, A.-L., Males, J. R., Marley, M., Morzinski, K., Oza, A., Patience, J., Rajan, A., Rieke, G., Schertl, D., Schlieder, J., Stone, J., Su, K., Vaz, A., Visscher, C., Ward-Duong, K., Weigelt, G., Woodward, C. E.  The LEECH Exoplanet Imaging Survey: Characterization of the Coldest Directly Imaged Exoplanet, GJ 504 b, and Evidence for Superstellar Metallicity 2016ApJ...817..166S

Available filesSizeCreated
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Semester Course Day/Time Location Resources
Spring 2017 ASTR 475-001
Spring 2017 PTYS 575-001

Last updated on May 7, 2018