Ph.D. Physics, The University of Toledo

2018

          Dissertation: Kepler Planet Occurrence Rates for Mid-Type M Dwarfs as a Function of Spectral Type
          Advisor: Prof. Michael C. Cushing

B.S. Astronomy, The University of Arizona

2011

Postdoctoral Research Associate, University of Arizona/Steward Observatory

2021-Present

          Advisor: Prof. Dániel Apai

Postdoctoral Scholar, Caltech/IPAC-NExScI

2018-2021

          Advisor: Dr. Jessie Christiansen

Visiting Graduate Fellow, IPAC

2017

          Advisor: Dr. Jessie Christiansen

Ritter Observatory Research Assistant, University of Toledo

2013-2017

          Advisor: Prof. Jon Bjorkman

Justin Klingele, undergraduate, University of Arizona

2021-2023

          Advised Justin as an Arizona/NASA Space Grant Intern to test optical diffuser performance on 1-m telescopes to improve photometry for exoplanet transits.

Kate Wienke, undergraduate, Kansas University

2022

          Co-advised Kate through the Caltech SURF program with Dr. Jessie Christiansen on a Spitzer exoplanet phase curve project.

Jillian Henkel, undergraduate, University of Toronto

2022

          Co-advised Jillian through the Caltech SURF program with Dr. Jessie Christiansen on a Spitzer exoplanet phase curve project.

Malhar Dave, undergraduate, University of Arizona

2022

          Advised Malhar on TESS TTV measurements.

Rachel B. Fernandes, Ph.D., University of Arizona/LPL

2020-2023

          Advised and worked with Rachel on exoplanet demographics projects while she was an IPAC visiting grad fellow and beyond. Rachel is now a President’s
          Postdoctoral Fellow at Penn State.

Jon K. Zink, Ph.D., University of California, Los Angeles

2019-2021

          Advised and worked with Jon on Scaling K2 projects while he was an IPAC visiting grad fellow and beyond. Jon is now NASA Sagan Fellow at Caltech.

NASA WIYN PI Data Awards -- 7 total awards: $109,400

2015-2018

          NASA/NSF Exoplanet Exploration Program awards to characterize M dwarfs for Kepler and TESS exoplanet demographics studies using WIYN.

40 Papers   |   3 Research Notes   |   1 Report to NASA   |   879 Citations   |   Link to ADS

Exoplanets     Stars     Brown Dwarfs     Education     Asteroids

44. No Evidence for More Earth-sized Planets in the Habitable Zone of Kepler's M versus FGK Stars
          Bergsten, G. J.; Pascucci, I.; Hardegree-Ullman, K. K. et al. 2023. AJ, in press.
43. Using Photometrically-Derived Properties of Young Stars to Refine TESS's Transiting Young Planet Survey Completeness
          Fernandes, R. B.; Hardegree-Ullman, K. K.; Pascucci, I. et al. submitted.
42. Bioverse: A Comprehensive Assessment of the Capabilities of Extremely Large Telescopes to Probe Earth-like O₂ Levels in Nearby Transiting Habitable Zone Exoplanets
          Hardegree-Ullman, K. K.; Apai, D.; Bergsten, G. J. et al. 2023. AJ, 165, 267.
41. Scaling K2. VI. Reduced Small-planet Occurrence in High-galactic-amplitude Stars
          Zink, J. K.; Hardegree-Ullman, K. K.; Christiansen, J. L. et al. 2023. AJ, 165, 262.
40. EDEN Survey: Small Transiting Planet Detection Limits and Constraints on the Occurrence Rates of Planets around Late-M Dwarfs within 15 pc
          Dietrich, J.; Apai, D.; Schlecker, M.; Hardegree-Ullman, K. K. et al. 2023. AJ, 165, 149.
39. Scaling K2. V. Statistical Validation of 60 New Exoplanets From K2 Campaigns 2-18
          Christiansen, J. L.; Bhure, S.; Zink, J. K.; Hardegree-Ullman, K. K. et al. 2022. AJ, 163, 254.
38. Final Report for SAG 22: A Target Star Archive for Exoplanet Science
          Hinkel, N. R. ; Pepper, J. ; Stark, C. C. et al. 2021. Final report to guide NASA exoplanet science.
37. Scaling K2. IV. A Uniform Planet Sample for Campaigns 1-8 and 10-18
          Zink, J. K.; Hardegree-Ullman, K. K.; Christiansen, J. L.; et al. 2021. AJ 162, 259.
36. K2-138 g: Spitzer Spots a Sixth Planet for the Citizen Science System
          Hardegree-Ullman, K. K.; Christiansen, J. L.; Ciardi, D. R.; et al. 2021. AJ 161, 219.
35. Scaling K2. III. Comparable Planet Occurrence in the FGK Samples of Campaign 5 and Kepler
          Zink, J. K.; Hardegree-Ullman, K. K.; Christiansen, J. L.; et al. 2020. AJ, 160, 94.
34. Scaling K2. II. Assembly of a Fully Automated C5 Planet Candidate Catalog Using EDI-Vetter
          Zink, J. K.; Hardegree-Ullman, K. K.; Christiansen, J. L.; et al. 2020. AJ, 159, 154.
33. Scaling K2. I. Revised Parameters for 222,088 K2 Stars and a K2 Planet Radius Valley at 1.9 R_⊕
          Hardegree-Ullman, K. K.; Zink, J. K.; Christiansen, J. L.; et al. 2020. ApJS, 247, 28.
32. Characterizing K2 Candidate Planetary Systems Orbiting Low-mass Stars. IV. Updated Properties for 86 Cool Dwarfs Observed during Campaigns 1-17
          Dressing, C. D.; Hardegree-Ullman, K. K.; Schlieder, J. E. et al. 2019. AJ, 158, 87.
31. Bright Opportunities for Atmospheric Characterization of Small Planets: Masses and Radii of K2-3 b, c, and d and GJ3470 b from Radial Velocity Measurements and Spitzer Transits
          Kosiarek, M. R.; Crossfield, I. J. M.; Hardegree-Ullman, K. K. et al. 2019. AJ, 157, 97.
30. Catalog of New K2 Exoplanet Candidates from Citizen Scientists
          Zink, J. K.; Hardegree-Ullman, K. K.; Christiansen, J. L. et al. 2019. RNAAS, 3, 43.
29. Kepler Planet Occurrence Rates for Mid-type M Dwarfs as a Function of Spectral Type
          Hardegree-Ullman, K. K.; Cushing, M. C.; Muirhead, P. S.; Christiansen, J. L. 2019. AJ, 158, 75.
28.   Spitzer Light Curves of the Young, Planetary-Mass TW Hya Members 2MASS J11193254-1137466AB and WISEA J114724.10-204021.3
          Schneider, A. C.; Hardegree-Ullman, K. K.; Cushing, M. C.; et al. 2018. AJ, 155, 238.
27. Investigating the Physical Properties of Transiting Hot Jupiters with the 1.5-m Kuiper Telescope
          Turner, J. D.; Leiter, R. M.; Biddle, L. I. et al. 2017. MNRAS, 472, 3871.
26.   Observed Variability at 1μm and 4μm in the Y0 Brown Dwarf WISEP J173835.52+273258.9
          Leggett, S. K.; Cushing, M. C.; Hardegree-Ullman, K. K.; et al. 2016. ApJ, 830, 141.
25. Ground-Based Near-UV Observations of 15 Transiting Exoplanets: Constraints on Their Atmospheres and No Evidence for Asymmetrical Transits
          Turner, J. D.; Pearson, K. A.; Biddle, L. I. et al. 2016. MNRAS, 459, 789.
24.   The First Detection of Photometric Variability in a Y Dwarf: WISE J140518.39+553421.3
          Cushing, M. C.; Hardegree-Ullman, K. K.; Trucks, J. L. et al. 2016. ApJ, 823, 152.
23. Near-UV and Optical Observations of the Transiting Exoplanet TrES-3b
          Turner, J. D.; Smart, B. M.; Hardegree-Ullman, K. K. et al., 2013. MNRAS, 428, 678.
22. A New Online Astronomy Resource for Education and Outreach
          Impey C. D.; Hardegree-Ullman, K. K.; Patikkal, A. et al. 2013. Astro. Ed. Rev., 12, 010301.

21. Clouds and Clarity: Revisiting Atmospheric Feature Trends in Neptune-size Exoplanets
          Brande, J.; Crossfield, I. J. M. ; Kreidberg, L. et al. 2023. ApJL, submitted.
20. Bioverse: The Habitable Zone Inner Edge Discontinuity as an Imprint of Runaway Greenhouse Climates on Exoplanet Demographics
          Schlecker, M.; Apai, D.; Lichtenberg, T. et al. 2023. PSJ, in press.
19. Water Absorption in the Transmission Spectrum of the Water World Candidate GJ 9827 d
          Roy, P.-A.; Benneke, B.; Piaulet, C. et al. 2023. ApJ, 954, 52.
18. The mass of TOI-519 b: A close-in giant planet transiting a metal-rich mid-M dwarf
          Kagetani, T.; Narita, N.; Kimura, T. et al. 2023. PASJ 75, 713.
17. Preliminary estimates of the Zwicky Transient Facility 'Ayló'chaxnim asteroid population completeness
          Bolin, B. T.; Ahumada, T.; van Dokkum, P. et al. 2023. Icarus 394, 115442.
16. The discovery and characterization of (594913) 'Ayló'chaxnim, a kilometre sized asteroid inside the orbit of Venus
          Bolin, B. T.; Ahumada, T.; van Dokkum, P. et al. 2022. MNRAS 517, 49.
15. The K2-3 System Revisited: Testing Photoevaporation and Core-powered Mass Loss with Three Small Planets Spanning the Radius Valley
          Diamond-Lowe, H.; Kreidberg, L.; Harman, C. E. et al. 2022. AJ 164, 172.
14. Tentative Evidence for Water Vapor in the Atmosphere of the Neptune-Size Exoplanet HD 106315 c
          Kreidberg, L.; Mollière, P.; Crossfield, I. J. M. et al. 2022. AJ 164, 124.
13. pterodactyls: A Tool to Uniformly Search and Vet for Young Transiting Planets In TESS Primary Mission Photometry
          Fernandes, R. B. ; Mulders, G. D. ; Pascucci, I. et al. 2022. AJ, 164, 78.
12. An Updated Ephemeris for K2-138 d
          Boyle, A.; Christiansen, J. L.; Vissapragada, S.; Hardegree-Ullman, K. K. 2022. RNAAS, 6, 71.
11. An exomoon survey of 70 cool giant exoplanets and the new candidate Kepler-1708 b-i
          Kipping, D.; Bryson, S.; Burke, C. et al. 2022. Nature Astronomy, 6, 367.
10. WASP-107b's Density Is Even Lower: A Case Study for the Physics of Planetary Gas Envelope Accretion and Orbital Migration
          Piaulet, C.; Benneke, B.; Rubenzahl R. A. et al. 2021. AJ, 161, 70.
9. Transmission spectroscopy for the warm sub-Neptune HD3167c: evidence for molecular absorption and a possible high metallicity atmosphere
          Mikal-Evans, T.; Crossfield, I. J. M.; Benneke, B. et al. 2021. AJ, 161, 18.
8. Revisiting the HIP 41378 System with K2 and Spitzer
          Berardo, D.; Crossfield, I. J. M.; Werner, M. et al. 2019. AJ, 157, 185.
7. An Updated Ephemeris for the Single-lined Orbit of the Supergiant μ Sagittarii
          Johnson, R. A.; Richardson, N. D.; Moffat, A. F. J. et al. 2018. RNAAS, 2, 138.
6. Characterizing K2 Candidate Planetary Systems Orbiting Low-Mass Stars III: A High Mass & Low Envelope Fraction for the Warm Neptune K2-55b
          Dressing, C. D.; Sinukoff, E.; Fulton, B. J. et al. 2018. AJ, 156, 70.
5. Planetary Candidates from K2 Campaign 16
          Yu, L.; Crossfield, I. J. M.; Schlieder, J, E. et al. 2018. AJ, 156, 22.
4.   2MASS J11151597+1937266: A Young, Dusty, Isolated, Planetary-Mass Object with a Potential Wide Stellar Companion
          Theissen, C. A.; Burgasser, A. J.; Bardalez Gagliuffi, D. C.; et al. 2018. ApJ, 853, 75.
3. The Most Massive Heartbeat: An In-Depth Analysis of Iota Orionis
          Pablo, H.; Richardson; N. D.; Fuller, J. et al. 2017. MNRAS, 467, 2494.
2. A Spectroscopic Orbit for the Late-type Be Star Beta CMi
          Dulaney, N. A.; Richardson, N. D.; Gerhartz, C. J. et al. 2017. ApJ, 836, 112.
1.   Photometric Monitoring of the Coldest Known Brown Dwarf with the Spitzer Space Telescope
          Esplin, T. L.; Luhman, K. L.; Cushing, M. C. et al. 2016. ApJ, 832, 58.

SOAR - NOIRLab Survey Program

2019-2022

          Atmospheric survey of hot Jupiters observed by TESS (Goodman).

30 nights

NASA IRTF

2016-2020

          Kepler M dwarfs and optical/IR metallicity calibration projects (SpeX).

17 nights

WIYN

2015-2018

          Kepler M dwarfs and TESS cool star characterization projects (Hydra).

46 nights

Lowell Discovery Telescope

2013-2017

          Kepler M dwarfs and transiting exoplanet projects (DeVeny, LMI).

20 nights

NOIRLab Mid-Scale Observatories Users' Committee

2022-Present

SOAR Telescope Science Advisory Committee

2020-Present

Subject-matter expert reviewer in NASA peer reviews

2020-Present

ExoPAG SAG #22 - Existing Stellar Catalogs Task Force Co-Lead

2020-2021

Referee for AAS Journals, MNRAS, PASP, and A & A

2018-Present

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