Zobrazeno 1 - 10
of 42
pro vyhledávání: '"Shreyas Vissapragada"'
Autor:
Shreyas Vissapragada, Patrick McCreery, Leonardo A. Dos Santos, Néstor Espinoza, Andrew McWilliam, Noriyuki Matsunaga, Jéa Adams Redai, Patrick Behr, Kevin France, Satoshi Hamano, Charlie Hull, Yuji Ikeda, Haruki Katoh, Hideyo Kawakita, Mercedes López-Morales, Kevin N. Ortiz Ceballos, Shogo Otsubo, Yuki Sarugaku, Tomomi Takeuchi
Publikováno v:
The Astrophysical Journal Letters, Vol 962, Iss 1, p L19 (2024)
The recent discovery of “ultrahot” ( P < 1 day) Neptunes has come as a surprise: some of these planets have managed to retain gaseous envelopes despite being close enough to their host stars to trigger strong photoevaporation and/or Roche lobe ov
Externí odkaz:
https://doaj.org/article/ccc1cd63fc4e4bcd8f9b79ffc4633e60
Autor:
W. Garrett Levine, Shreyas Vissapragada, Adina D. Feinstein, George W. King, Aleck Hernandez, Lía Corrales, Michael Greklek-McKeon, Heather A. Knutson
Publikováno v:
The Astronomical Journal, Vol 168, Iss 2, p 65 (2024)
Aeronomy, the study of Earth’s upper atmosphere and its interaction with the local space environment, has long traced changes in the thermospheres of Earth and other solar system planets to solar variability in the X-ray and extreme-ultraviolet (co
Externí odkaz:
https://doaj.org/article/1d574615dd3248689cb40a5e5fba837b
Autor:
Samuel K. Grunblatt, Nicholas Saunders, Daniel Huber, Daniel Thorngren, Shreyas Vissapragada, Stephanie Yoshida, Kevin C. Schlaufman, Steven Giacalone, Mason Macdougall, Ashley Chontos, Emma Turtelboom, Corey Beard, Joseph M. Akana Murphy, Malena Rice, Howard Isaacson, Ruth Angus, Andrew W. Howard
Publikováno v:
The Astronomical Journal, Vol 168, Iss 1, p 1 (2024)
Hot Neptunes, gaseous planets smaller than Saturn (∼3–8 R _⊕ ) with orbital periods less than 10 days, are rare. Models predict this is due to high-energy stellar irradiation stripping planetary atmospheres over time, often leaving behind only
Externí odkaz:
https://doaj.org/article/60a3ed11600f46b49d2be5cb04e96478
Autor:
Jorge Pérez-González, Michael Greklek-McKeon, Shreyas Vissapragada, Morgan Saidel, Heather A. Knutson, Dion Linssen, Antonija Oklopčić
Publikováno v:
The Astronomical Journal, Vol 167, Iss 5, p 214 (2024)
Photoevaporative mass-loss rates are expected to be highest when planets are young and the host star is more active, but to date there have been relatively few measurements of mass-loss rates for young gas giant exoplanets. In this study we measure t
Externí odkaz:
https://doaj.org/article/5f301d5bedce460f988e50d96c640f46
Autor:
Shreyas Vissapragada, Michael Greklek-McKeon, Dion Linssen, Morgan MacLeod, Daniel P. Thorngren, Peter Gao, Heather A. Knutson, David W. Latham, Mercedes López-Morales, Antonija Oklopčić, Jorge Pérez González, Morgan Saidel, Abigail Tumborang, Stephanie Yoshida
Publikováno v:
The Astronomical Journal, Vol 167, Iss 5, p 199 (2024)
Superpuffs are planets with exceptionally low densities ( ρ ≲ 0.1 g cm ^−3 ) and core masses ( M _c ≲ 5 M _⊕ ). Many lower-mass ( M _p ≲ 10 M _⊕ ) superpuffs are expected to be unstable to catastrophic mass loss via photoevaporation and/
Externí odkaz:
https://doaj.org/article/befb1ce6c87345458df59c4c423d829f
Autor:
Stephanie Yoshida, Shreyas Vissapragada, David W. Latham, Allyson Bieryla, Daniel P. Thorngren, Jason D. Eastman, Mercedes López-Morales, Khalid Barkaoui, Charles Beichman, Perry Berlind, Lars A. Buchave, Michael L. Calkins, David R. Ciardi, Karen A. Collins, Rosario Cosentino, Ian J. M. Crossfield, Fei Dai, Victoria DiTomasso, Nicholas Dowling, Gilbert A. Esquerdo, Raquel Forés-Toribio, Adriano Ghedina, Maria V. Goliguzova, Eli Golub, Erica J. Gonzales, Ferran Grau Horta, Jesus Higuera, Nora Hoch, Keith Horne, Steve B. Howell, Jon M. Jenkins, Jessica Klusmeyer, Didier Laloum, Jack J. Lissauer, Sarah E. Logsdon, Luca Malavolta, Rachel A. Matson, Elisabeth C. Matthews, Kim K. McLeod, Jennifer V. Medina, Jose A. Muñoz, Hugh P. Osborn, Boris Safonov, Joshua Schlieder, Michael Schmidt, Heidi Schweiker, Sara Seager, Alessandro Sozzetti, Gregor Srdoc, Guđmundur Stefánsson, Ivan A. Strakhov, Stephanie Striegel, Joel Villaseñor, Joshua N. Winn
Publikováno v:
The Astronomical Journal, Vol 166, Iss 5, p 181 (2023)
We present the discovery of TOI-1420b, an exceptionally low-density ( ρ = 0.08 ± 0.02 g cm ^−3 ) transiting planet in a P = 6.96 days orbit around a late G-dwarf star. Using transit observations from TESS, LCOGT, Observatoire Privé du Mont, Whit
Externí odkaz:
https://doaj.org/article/3851d74f306a41f3b36345f80e93f704
Autor:
Aaron Bello-Arufe, Heather A. Knutson, João M. Mendonça, Michael M. Zhang, Samuel H. C. Cabot, Alexander D. Rathcke, Ana Ulla, Shreyas Vissapragada, Lars A. Buchhave
Publikováno v:
The Astronomical Journal, Vol 166, Iss 2, p 69 (2023)
Extremely low-density exoplanets are tantalizing targets for atmospheric characterization because of their promisingly large signals in transmission spectroscopy. We present the first analysis of the atmosphere of the lowest-density gas giant current
Externí odkaz:
https://doaj.org/article/93603824381d4862b400f75a1165f725
Publikováno v:
The Astronomical Journal, Vol 165, Iss 6, p 244 (2023)
Hydrodynamic atmospheric escape is considered an important process that shapes the evolution of sub-Jovian exoplanets, particularly those with short orbital periods. The metastable He line in the near-infrared at 1.083 μ m is a reliable tracer of at
Externí odkaz:
https://doaj.org/article/930a5263554343a1b543fac67f4a6a35
Autor:
Michael Greklek-McKeon, Heather A. Knutson, Shreyas Vissapragada, Daniel Jontof-Hutter, Yayaati Chachan, Daniel Thorngren, Gautam Vasisht
Publikováno v:
The Astronomical Journal, Vol 165, Iss 2, p 48 (2023)
Kepler-289 is a three-planet system containing two sub-Neptunes and one cool giant planet orbiting a young, Sun-like star. All three planets exhibit transit timing variations (TTVs), with both adjacent planet pairs having orbital periods close to the
Externí odkaz:
https://doaj.org/article/a5d727fce39441e2a4eb376632631cdd
Autor:
Fei Dai, Kento Masuda, Corey Beard, Paul Robertson, Max Goldberg, Konstantin Batygin, Luke Bouma, Jack J. Lissauer, Emil Knudstrup, Simon Albrecht, Andrew W. Howard, Heather A. Knutson, Erik A. Petigura, Lauren M. Weiss, Howard Isaacson, Martti Holst Kristiansen, Hugh Osborn, Songhu Wang, Xian-Yu Wang, Aida Behmard, Michael Greklek-McKeon, Shreyas Vissapragada, Natalie M. Batalha, Casey L. Brinkman, Ashley Chontos, Ian Crossfield, Courtney Dressing, Tara Fetherolf, Benjamin Fulton, Michelle L. Hill, Daniel Huber, Stephen R. Kane, Jack Lubin, Mason MacDougall, Andrew Mayo, Teo Močnik, Joseph M. Akana Murphy, Ryan A. Rubenzahl, Nicholas Scarsdale, Dakotah Tyler, Judah Van Zandt, Alex S. Polanski, Hans Martin Schwengeler, Ivan A. Terentev, Paul Benni, Allyson Bieryla, David Ciardi, Ben Falk, E. Furlan, Eric Girardin, Pere Guerra, Katharine M. Hesse, Steve B. Howell, J. Lillo-Box, Elisabeth C. Matthews, Joseph D. Twicken, Joel Villaseñor, David W. Latham, Jon M. Jenkins, George R. Ricker, Sara Seager, Roland Vanderspek, Joshua N. Winn
Publikováno v:
The Astronomical Journal, Vol 165, Iss 2, p 33 (2023)
Convergent disk migration has long been suspected to be responsible for forming planetary systems with a chain of mean-motion resonances (MMRs). Dynamical evolution over time could disrupt the delicate resonant configuration. We present TOI-1136, a 7
Externí odkaz:
https://doaj.org/article/170b4ba8291c483d9b8fb10bb0173bba