Members (and guests!) of the Cool Star Lab in Summer 2017. Top row from left: Joshua Hazlett, Dorsa Majidi, Stella Zhang, Carolina Herrara Hernandez, Diego Octavio Talavera Maya, Niana Mohammed. Bottom row from left: Steven Truong, Gretel Mercado, Debby Tran, Elizabeth Hilario Moreno, Luis Nunez, and Adam Burgasser.

The Cool Star Lab has included high school students, undergraduate students, graduate students, and research and educational staff at UC San Diego, and occasional visitors from around the region and the world.  Our research undergraduates have gone on to top graduate schools, earned prized graduate and postdoctoral fellowships, and have embarked on careers in academia and industry.

Research Staff

Dr. Carl Melis is an Assistant Research Scientist at UCSD and former NSF Astronomy and Astrophysics and CASS Postdoctoral Fellow and Chancellor’s Postdoctoral Scholar Award recipient.  His research  focuses on the birth, life, death, and re-birth of planetary systems with an emphasis on terrestrial (Earth-like) planets.


Chris Theissen (PhD Astronomy 2017, Boston University) was a visiting graduate student at UCSD, then awarded both NSF and Sagan Postdoctoral Fellowships.  Originally from San Diego, Chris’s research focuses on low-mass stars, including planetary evolution around small stars, and he has participated in UCSD’s Faculty and Student Team (FAST) Initiative site.  Chris was also a Ford Foundation Fellow.

Graduate Students

15576549005_fa0698faac_zChristian Aganze (BS Physics 2016 Morehouse College) was previously a summer undergraduate research student in the Cool Star Lab through the UCSD-Morehouse-Spelman Physics Bridge program. After earning his Bachelor’s in Physics and Dual-career Engineering major at Morehouse College in 2016, he has come to UCSD as a graduate student in Physics. He has analyzed the spectra of brown dwarfs using SPLAT, the HST-WISP survey, and most recently SDSS-APOGEE through UCSD’s Faculty and Student Team (FAST) Initiative site. He is also a member of the inaugural member of the LSST Data Science Fellowship program. Christian is originally from Rwanda.

Chih-Chun “Dino” Hsu is a graduate student who is originally from Taiwan, and started working in the Cool Star Lab in 2016. His work focuses on high resolution spectroscopy of ultracool dwarfs using archival data. In 2019, he was awarded a Lattimer Award for Graduate Excellence.

Roman Gerasimov is a graduate student who started working in the Cool Star Lab in 2018. Roman earned his Bachelor’s degree at University College London, and splits his time between cool stars and cosmology. Roman has been developing new atmospheric models for ultracool dwarfs with non-solar abundances for investigations of globular cluster populations.

Undergraduate Students

Christopher Danner is a Physics major who started working in the Cool Star Lab in 2020. He is analyzing archival SpeX data for ultracool dwarfs in the IRTF Archive.

Ryan Low is a Physics major who started working in the Cool Star Lab in 2018. His senior thesis project focuses on analyzing optical spectra of ultracool dwarfs obtained with the Lick/KAST instrument. He was awarded a Dean’s Undergraduate Award for Excellence in 2019.

Niana Mohammed is a Physics major was started working in the Cool Star Lab in 2017. She has contributed to the reduction of SpeX data in the IRTF archive and development of the SPLAT code.

Tianxing Wang is a Physics major who started working in the Cool Star Lab in 2019. He is analyzing archival SpeX data for ultracool dwarfs in the IRTF Archive.

 Visiting scholars

Eduardo Martín Guerrero is a CSIC Research Professor based on the Centro de Astrobiologia (INTA-CSIC) in Madrid, Spain. One of the founding researchers in the field of brown dwarf astrophysics, he has part of the team to discover one of the first brown dwarfs, Teide 1, in 1994. He is visiting UCSD as part of Spain’s Salvador de Madariaga mobility program for senior researchers, with the primary goal of planning for brown dwarf observations using the future ESA Euclid satellite.

Former Lab Members

Athena Ababao (BS Biochemistry 2019 UCSD) was a UCSD research student and member of the Cool Star Lab in 2018 who contributed to analysis of SpeX archival data.

IMG_0053Miriam Aberasturi (PhD Astrophysics 2015 U. de Madrid) was a visiting graduate student from Centro de Astrobiologia in Madrid, Spain, working on Hubble Space Telescope observations of late L and T dwarfs to assess the multiplicity rate across the L dwarf/T dwarf transition.  She spent 6 months in late 2012 in residence at UCSD, completed her thesis in 2015, and is now a research scientist at ESO-Madrid.

Natasha Banchik (BS Physics 2013 UCSD; MS Education 2015 UCSD) was an undergraduate research assistant on both the Beach Physics project and Project Planetaria. She is now a Physics teacher in Hoover High School in the San Diego Unified School District.

IMG_0062Daniella Bardalez Gagliuffi (BS Physics MIT 2011; PhD Physics UCSD 2017) completed her PhD in Physics at UC San Diego on the thesis topic of spectral binaries composed of late-M, L and T dwarfs.  A native of Peru, Daniella previously earned her Bachelor’s in Physics from MIT in 2011 where she worked on brown dwarfs, galaxy formation, and damped Lyman alpha systems. Daniella earned several awards and scholarships while in the Cool Star Lab, including an International Center Fellowship, an IPAC Visiting Graduate Student Fellowship, an AWIS Graduate Scholarship, and a Sigma Xi scholarship; and was inducted into the Bouchet Scholar Society. Daniella is now a postdoctoral fellow at the American Museum of Natural History.


Clara Bennett (BS Physics 2011 MIT) was an undergraduate researcher working on the Spitzer/IRAC photometry of very low mass stars and brown dwarfs.  Last check, Clara was working at NASA Goddard Spaceflight Center.

Kieran Berton is a Physics major at St. Olaf’s College who has worked with Carl Melis over two summers on Hamilton echelle spectroscopic observations of young stars in the Pleiades.

Screen Shot 2016-08-21 at 10.55.07 PMJessica Birky started working in the Cool Star Lab in 2016. In addition to contributing to the SPLAT program, she focused on analysis of high-resolution SDSS-APOGEE spectra of late-M and L dwarfs through UCSD’s Faculty and Student Team (FAST) Initiative site. Jessica graduated in 2019 and is now a graduate student at the U. Washington with an NSF Graduate Research Fellowship.

John Bochanski was a postdoctoral researcher in the Burgasser Lab at MIT, working on construction and software development of the FIRE spectrograph and kinematic investigations of M, L and T dwarfs.  He specializes in the use of large surveys to study the formation and evolution of the Galaxy, and is active member of the LSST Consortium. He is now an Assistant Professor at Rider University and an active blogger at Sky and Telescope.


emilyEmily Bowsher was a Research Assistant/Engineer working on astronomical instrumentation development. She did a concept study for wide-field imaging instrument (called Cerberus) for the Lick Observatory.  Last check, Emily was a research assistant at Columbia University.

7479774698_408a402006Amelia Christensen (BS/MS Electrical Engineering 2013 UCSD) was an undergraduate researcher investigating the variability of L dwarfs in the Catalina Rapid Transient Survey.  Her xcde-style poster presentation at the 220th meeting of the American Astronomical Society earned a Chambliss Astronomy Achievement Student Award honorable mention.  She is currently a graduate student at Stanford.

Caleb Choban (BS Physics 2016 UCSD) worked on machine-learning algorithms to define optimal near-infrared indices for segregating spectral subclasses of M, L and T dwarfs, and was a lead code developer for SPLAT. He stayed on at UCSD for his Physics PhD, working primarily in numerical simulation with Prof. Dusan Keres.

IMG_0067Dianna Cowern (BS Physics MIT 2011) was a science outreach coordinator and Creative Director for Beach Physics.  Hailing from Kauai, Hawaii, Dianna earned her Bachelor’s in Physics from MIT in 2011, and has done research on dark matter and low-metallicity stars. After winning the 2014 Alan Alda Flame Challenge, Dianna has become a science education superstar as YouTube’s Physics Girl,

[Beach Physics] [Physics Woman]

Screen Shot 2016-08-21 at 10.50.25 PMAndrew Davis is an Applied Physics and Dual-degree Engineering major at Morehouse College, who participated in the 2016 UCSD-Morehouse-Spelman Physics Bridge program. He led development of the SPLAT Web Interface and contributed to data reduction of SpeX brown dwarf spectra. Andrew aims to get a PhD in Aerospace Engineering and become a research engineer at NASA. An avid gamer, he also wants to create and implement new technology to create gaming platforms, and develop games that inspire people to make the world a better place.

14955822094_4470c80772_zIvanna Escala (BS Physics 2015 UCSD) graduated at the top of her class from UCSD, and is now a graduate student in the Department of Astronomy at Caltech. Ivanna developed techniques to determine the physical properties of a set of unusually magnetically active T-type brown dwarfs. Ivanna earned both an NSF Graduate Fellowship and Ford Foundation Fellowship in 2016.

661258e3d122d0b2357153bf3681db66Jacqueline Faherty (PhD Astronomy 2010 SUNY Stony Brook) is an expert in infrared astrometry and cool dwarf populations, and developed and led the Brown Dwarf Kinematics Project as her graduate thesis.  An International NSF Fellow at U. de Chile and Hubble Fellow at Carnegie Department of Terrestrial Magnetism in Washington, DC, Jackie will soon be joining the science staff at the American Museum of Natural History.

[homepage] [BDKP]

Sarah Garcia (BS Physics 2011 UCSD) was an undergraduate researcher measuring Spitzer/IRAC photometry for very low mass dwarfs. She is also an accomplished dancer.  At last check, she was teaching Physics at High Tech High.

salSalvador Guiterrez
 (BS Electrical Engineering 2010 UCSD) was an undergraduate McNair Research Scholar working on Beach Physics.  At last check, he was a Electronics Engineer at Watt Stopper/Legrand.

Joshua Hazlett participated in the UCSD-Morehouse-Spelman Bridge program in 2017, working on a web-based interface for the SPLAT program.

Carolina Herrara Hernandez was a high school student from Mexico who participated in summer research in 2017 through the the bi-national ENLACE program. She analyzed resolved ultracool dwarf binaries with imaging and spectral data.

Screen Shot 2016-08-21 at 10.58.31 PMElizabeth Moreno Hilaro was a Physics major at the Universidad de Guanajuato, Mexico when she joined the Cool Star Lab in 2016 and 2017 through the UCSD STARS program. She contributed to the SPLAT project and led spectral and imaging analysis of several late-M dwarf binaries. She is now a graduate student at the University of La Serena, Chile.

aishaAishwarya (“Aisha”) Iyer (BS Physics 2015 UCSD) examined  mid-infrared variability in the TWA 30AB system using Spitzer photometry, and was a SURF fellow at Caltech. She is now a Master’s student at CSU Northridge, where she is working with Mark Swain at NASA JPL to study exoplanet transmission spectra. Originally from Mumbai, India, Aishwarya is a vegan cook, animal welfare supporter, and she sketches comic book superheroes for leisure.

15389947749_09843400e8_zYuhui Jin (BS Physics, Math 2017 UCSD) worked in the Cool Star Lab in 2013-2014 where she analyzed survey data on astronomer’s perspectives on the definition of a planet, contributed code to the SPLAT project, and compared models to MLT spectra in the SpeX Prism Library to measure physical properties. Yuhui is now in the graduate program in Math at Caltech.

315022_10101961034268413_1468785015_nHarish Khandrika (MS Astronomy 2013 SDSU) was a Davidson Fellow at UC Berkeley and a research assistant in the Burgasser Lab studying weather-related variability in L and T dwarfs using Lick/Gemini. He published this work in 2013, earned his Master’s in Astronomy at SDSU, and is now a research scientist at Space Telescope Science Institute. He is also a gifted photographer.

[Harish K Photography]

EmilyLevesqueEmily Levesque (BS Physics 2006 MIT) was an undergraduate researcher working on the observational properties of supergiant stars.  She earned her PhD in Astronomy from U. Hawaii in 2010 for which she was awarded the Robert J. Trumpler award in 2012.  Emily has been an Einstein Postdoctoral Fellow, a Hubble Postdoctoral Fellow, and recipient of the Annie Jump Cannon Prize, and is now an Assistant Professor at the University of Washington.


logsdonSarah Logsdon (BS Physics 2011 UCSD, PhD Astrophysics 2017 UCLA) was an undergraduate researcher examining the kinematics of late M and L dwarfs using optical spectroscopy obtained with the Magellan/MagE spectrograph.  She earned a Physical Sciences Dean’s Undergraduate Awards for Excellence in 2010.  She completed her PhD in the Physics and Astronomy Department at UCLA and is now at NASA Goddard on a NASA Postdoctoral Program Fellowship.

MV5BMTM1NTIzNDU0Nl5BMl5BanBnXkFtZTcwODA0OTU4Mw@@._V1._SX640_SY962_Dagny Looper (PhD Astronomy 2011 U. Hawaii) led numerous investigations on very low mass stars and cool brown dwarfs, investigating atmospheric properties, multiplicity and low-mass objects in nearby moving groups.  Her thesis work uncovered several new low-mass stars and brown dwarfs in the TW Hydrae association, including a remarkable wide pair of disk-obscured, jet-emitting M dwarfs TWA 30AB.  She recently completed her MFA in Cinema at New York University.

[Black Sunday Pictures] [IMDB]

14122239568_9e3234894b_zMike Lopez (BS Physics 2015 UCSD, MS Physics Education 2018 Ohio State University) was a McNair Scholar at UCSD and an undergraduate researcher in the Cool Star Lab. He worked on SPLAT, developing tools to identify and characterize the first planetary-mass brown dwarf found in the young 32 Orionis cluster. Mike also conducted Physics Education Research in our group, analyzing detailed student test performance in our 2015 Cooperative Problem Solving model experiment; and at the University of Colorado, Boulder. A participant in the APS Bridge Program, Mike did graduate research at the Ohio State University Department of Physics earning a Master’s degree in 2018.


Rosalinda Lopez is an Astrophysics major at UCLA who worked with Carl Melis on radio monitoring observations of the hyperactive L dwarf 2MASS 1315-2649AB.

8454128162_7caebcfecbChristopher Luk (BS Physics 2012 UCSD) was an undergraduate researcher analyzing Keck/NIRSPEC spectra of very low mass stars, in particular spectral binaries.  He is also a highly skilled archer.  He is currently pursuing his PhD degree in Material Science.

Dorsa Majidi was a Physics major at Palomar College who joined the Cool Star Lab in 2017 as part of the UCSD STARS program. Dorsa helped develop database tools for the SPLAT code, and presented her work at SACNAS and AAS national conferences. She is now an undergraduate Astronomy major at UCLA.

Diego Octavio Talavera Maya (BS Aerospace Engineering 2018 UABC) was a summer research student from Mexico who participated in the bi-national ENLACE program in 2017. He analyzed resolved ultracool dwarf binaries with imaging and spectral data. He is now pursuing his “Space Masters” at Lulea University in Sweden.

constantinosConstantinos Melachrinos (BS Physics 2008 MIT, PhD Physics 2013 U Chicago) was an undergraduate researcher at MIT working on searches for ultracool subdwarfs.  He earned his PhD from the University of Chicago working on the Atlas Experiment at CERN, and is now teaching physics at the Department of Electrical and Computer Engineering at Cyprus University of Technology.

rp_gretel-e1453337965365.jpgGretel Mercado (BS Physics 2018 UCSD) was a Physics major and Computer Science minor who used SPLAT tools to investigate a new L dwarf companion to a nearby sun-like star. She participated in the CAMP program and was on the leadership of the Undergraduate Women in Physics group, and helped to organize the APS Conference for Undergraduate Women in Physics hosted by UCSD in 2016. Gretel earned her Bachelors in Physics in 2018.

IMG_0080Jason Morpeth (BS Physics 2013 UCSD) was an undergraduate researcher who did database management for the SpeX Prism Spectral Libraries and investigated quantitative metrics for identifying brown dwarfs in large surveys.

Christine Nicholls was a postdoctoral researcher at UC San Diego from 2011-2013.  Her research focuses on  stellar evolution and variability, particularly among red giant stars, and using photometric and radial velocity techniques to study binaries containing giant stars and brown dwarfs.

Jon Parra (BS Astronomy 2014 UCSC) was a pre-doctoral student working on simulating brown dwarf populations in the local Galaxy for the SPLAT code. He graduated from UCSC with a BS in Astronomy in 2014.

Dillon Peng (BS Physics 2019 UCSD) was a Physics major who started working in the Cool Star Lab in 2018. He analyzed archival SpeX data for ultracool dwarfs in the IRTF Archive, and is now working with Prof. Quinn Konopacky during his “gap” year.

188875_613195803538_6507688_nSebastian Pineda (BS Physics 2010 MIT, PhD Astronomy Caltech 2016) was an undergraduate researcher at MIT working on the activity and kinematic distributions of M dwarfs in the SDSS survey.  He completed his PhD as an NSF Graduate Fellow in the Department of Astronomy at Caltech, and is now a postdoctoral researcher at the University of Colorado Boulder. He also had a cameo in The PhD Movie.

IMG_0011Guido Roberts-Borsani was a visiting undergraduate student from the University of Kent, who performed numerical simulations of local brown dwarf populations to assess binary properties from limited observations. He is now at University College London working on galaxy formation and evolution

Screen Shot 2016-08-21 at 11.07.16 PMIsabela Rodrigues joined the Cool Star Lab in 2016 as a summer research student through the Brazil Institute of International Education Scientific Mobility Program. Here, she used word frequency software to analyze student writing from the Physics 1A Cooperative Problem Solving experiment to compare and assess the evolution of student sentiment between lecture and workshop models. She presented her work at the 2016 Physics Education Research Conference in Sacramento, CA.

15552854976_b15f064bdf_zMaitrayee Sahi is a Noyce Master Teacher at Garfield High School who worked in the Cool Star Lab through the Industry Initiatives for Science and Math Education (IISME) program. She worked on the SPLAT project and fitting models to the spectra of the coldest T dwarfs.


Nathan Schram (BS Physics and Astronomy 2013 UC Riverside) was an undergraduate research from Palomar College who investigated variability in low mass stars in TW Hydrae.  He transferred to UC Riverside in 2011 and graduated with a BS in Physics and Astronomy in 2013.

Screen Shot 2016-08-21 at 10.47.37 PMGuillaume Shippee was a summer research student in the Cool Star Lab in 2016, and currently attends UC Berkeley. He made major contributions to SPLAT Web Interface and is working with Chris Theissen on finding new nearby cool dwarfs through the SDSS LateMOVERS program.

Breann Sitarksi (PhD Astrophysics 2016 UCLA) was a graduate student in Physics at UC San Diego in 2011, where she worked on Keck/OSIRIS spectroscopic observations of the brown dwarf binary 2MASS J1315-2649AB.  She completed her PhD in 2016 from UCLA in the Ghez group.

melisaMelisa Tallis
 (BS Physics 2016 UCSD) was part of the a Cool Star Lab from 2013-2016, where she searched for young M and L dwarfs using the SpeX Prism Library; and contributed to the construction of a prototype sound planetarium through the cosmOcosm collaboration.  In 2014, she earned a Dynes Scholarship for Summer Undergraduate Research. Originally from Buenos Aires, Argentina, Melisa has played for the UCSD’s women’s soccer team, is an avid bicyclist and an enjoyer of eclectic music. She has worked for the Gemini Planet Imager Extrasolar Planet team at Stanford University.

16632436189_7b3275749f_zTomoki Tamiya (BS Physics 2016 UCSD) was a Physics major who started working in the Cool Star Lab in 2015. He contributed to coding development for the SPLAT project and investigated the spectra of a resolved pair of late-type M dwarf binaries. Tomoki is originally from Kobe, Japan.

14957141577_98dbc9132c_zJake Todd was an undergraduate at UCLA, who worked with Carl Melis on H-alpha monitoring observations of the nearby M9 dwarf 2MASS J0720-0846.

903118_4440607188352_799564426_oCharae Tongg (BS Computer Science 2015 Boston College) was a high school student at Seabury Academy who worked on the outreach project Astrofacts!  She is now a software developer at Spotify.

Steven Truong was a CAMPARE scholar from SDSU who worked in the Cool Star Lab in the summer of 2017. His research aimed to develop a web interface for the SPLAT program.

Screen Shot 2016-08-21 at 11.01.31 PM

Russell van Linge (BS Physics 2019 UCSD) was a Physics major at Palomar College (taught by the great Takashi Nakajima!) who joined the Cool Star Lab as a summer student in 2016 through the CAMPARE program. Russell worked on analysis of JVLA radio monitoring data of the low-mass radio-emitting binaries 2MASS 1315-2649AB and NLTT 33370AB in collaboration with Carl Melis and Peter Williams at Harvard. He also contributed to the SPLAT Web Interface. He transferred to UCSD in 2017 and earned his Bachelor’s degree in 2019. He is now an analyst in a local consulting company.

ALIENWORLDAndrew West was a postdoctoral fellow at MIT, working on M dwarf population studies using large surveys.  He is an expert on low-mass stars, magnetic activity, and the properties of nearby galaxies.  Andrew was a Professor of Astronomy at Boston University, where his class “Alien Worlds” was been called one of the 10 Craziest College Classes.

Ruiyu Zhang (BS Computer Science 2019 UCSD) was a UCSD research student and member of the Cool Star Lab in 2018-2019 who contributed to analysis of SpeX archival data.