Results 61 to 70 of about 3,196,959 (228)

A Solar Analog Model for Decrease in Far Ultraviolet Irradiance Under a Grand Minimum

Earth and Space Science, Volume 13, Issue 9, September 2026.
Abstract Solar analog field stars having a range of magnetic activity can provide an estimate of solar spectral irradiance (SSI) variability relevant to understanding the Sun's influence on terrestrial climate. This approach is particularly useful for far ultraviolet (FUV) irradiance that cannot be observed from the Earth surface.
D. Lubin, C. Melis, D. Tytler
wiley   +1 more source

Amplifying Resonant Repulsion with Inflated Young Planets, Overlooked Inner Planets, and Nonzero Initial Δ

The Astrophysical Journal
Most multiplanet systems around mature (∼5 Gyr old) host stars are nonresonant. Even the near-resonant planet pairs still display 1%–2% positive deviation from perfect period commensurabilities (Δ) near first-order mean motion resonances (MMRs). Resonant
Yuancheng Xu, Fei Dai
doaj   +1 more source

Atmospheres on Nonsynchronized Eccentric-tilted Exoplanets. I. Dynamical Regimes [PDF]

The Astrophysical Journal, 2019
Abstract Relatively long-period, nonsynchronized planets—such as warm Jupiters—potentially retain the primordial rotation, eccentricity, and obliquity that might encapsulate information on planetary climate and formation processes. To date, there has not been a systematic study on climate patterns on these planets that will significantly
Kazumasa Ohno, Xi Zhang
openaire   +2 more sources

Exoplanet biosignatures : a review of remotely detectable signs of life [PDF]

, 2017
In the coming years and decades, advanced space- and ground-based observatories will allow an unprecedented opportunity to probe the atmospheres and surfaces of potentially habitable exoplanets for signatures of life.
Grenfell, John Lee, Lyons, Timothy W., Meadows, Victoria S, Nancy Y. Kiang, Siddharth Hegde, Meadows, Victoria S., Chester E. Harman, Edward W. Schwieterman, Timothy W. Lyons, Hu, Renyu, Renyu Hu, Cockell, Charles S, Parenteau, Mary N., DasSarma, Shiladitya, Sarah Rugheimer, Fisher, Theresa M., Christopher T. Reinhard, Shiladitya DasSarma, Hilairy E. Hartnett, Victoria S. Meadows, Walker, Sara L., Kiang, Nancy Y, Sara I. Walker, Parenteau, Mary N, Harman, Chester E, Olson, Stephanie L, Schwieterman, Edward W., Hegde, Siddharth, John Lee Grenfell, Hartnett, Hilairy E., Walker, Sara I., Fisher, Theresa M, Reinhard, Christopher T., Mary N. Parenteau, Giada N. Arney, Rugheimer, Sarah, Reinhard, Christopher T, Schwieterman, Edward W, Arney, Giada N, Hartnett, Hilairy E, Harman, Chester E., Cockell, Charles S., Stephanie L. Olson, Charles S. Cockell, Arney, Giada N., Lyons, Timothy W, Kiang, Nancy Y., Walker, Sara I, Olson, Stephanie L., Theresa M. Fisher   +49 more
core   +1 more source

Statistical Scale Analyses of a Diurnal Periodicity in Auroral Kilometric Radiation, Observed by Wind/WAVES

Journal of Geophysical Research: Space Physics, Volume 131, Issue 9, September 2026.
Abstract The Earth's strongest natural radio emission is Auroral Kilometric Radiation (AKR), which is correlated with auroral intensity, and is a barometer for space weather. AKR is generated by the electron cyclotron maser instability, with sources on auroral field lines. Previous work on AKR and radio emissions from other planets (or stars) points to
Alexandra Ruth Fogg, S. Wu, C. M. Jackman, S. J. Walker, M. J. Rutala, C. K. Louis, S. M. Ivanov, L. Lamy, J. E. Waters, D. K. Whiter   +9 more
wiley   +1 more source

Formation of Ultra-short-period Planets in Hot Jupiter Systems: Application to WASP-47

The Astrophysical Journal Letters
The WASP-47 system is notable as the first known system hosting both inner and outer low-mass planetary companions around a hot Jupiter, with an ultra-short-period (USP) planet as the innermost planetary companion.
Su Wang, Mengrui Pan, Yao Dong, Gang Zhao, Jianghui Ji   +4 more
doaj   +1 more source

Inferring Io's Internal Properties by Combining Gravity Measurements and Volcanic Activity

Journal of Geophysical Research: Planets, Volume 131, Issue 9, September 2026.
Abstract With its extreme geological activity, Io represents an archetype for tidally heated exoplanets/moons and provides insight into early stages of terrestrial planet evolution. Decades of ground‐based observations and multiple space missions have refined our understanding of Io, yet it remains debated where inside Io the tidal heating takes place.
A. Veenstra, M. Rovira‐Navarro, W. van der Wal   +2 more
wiley   +1 more source

The HD 191939 Exoplanet System is Well Aligned and Flat

The Astronomical Journal
We report the sky-projected spin–orbit angle λ for HD 191939 b, the innermost planet in a six-planet system, using Keck/KPF to detect the Rossiter–McLaughlin (RM) effect.
Jack Lubin, Erik A. Petigura, Judah Van Zandt, Corey Beard, Fei Dai, Samuel Halverson, Rae Holcomb, Andrew W. Howard, Howard Isaacson, Jacob Luhn, Paul Robertson, Ryan A. Rubenzahl, Guđmundur Stefánsson, Joshua N. Winn, Max Brodheim, William Deich, Grant M. Hill, Steven R. Gibson, Bradford Holden, Aaron Householder, Russ R. Laher, Kyle Lanclos, Joel Payne, Arpita Roy, Roger Smith, Abby P. Shaum, Christian Schwab, Josh Walawender   +27 more
doaj   +1 more source

Tidal synchronization of close-in satellites and exoplanets: II. Spin dynamics and extension to Mercury and exoplanet host stars [PDF]

Celestial Mechanics and Dynamical Astronomy, 2015
This paper deals with the application of the creep tide theory (Ferraz-Mello, CeMDA 116, 109, 2013) to the rotation of close-in satellites, Mercury, close-in exoplanets and their host stars. The solutions show two extreme cases: close-in giant gaseous planets, with fast relaxation (low viscosity) and satellites and Earth-like planets, with slow ...
openaire   +3 more sources

The Habitable Exoplanet Observatory (HabEx) [PDF]

, 2018
The Habitable-Exoplanet Observatory (HabEx) is a candidate flagship mission being studied by NASA and the astrophysics community in preparation of the 2020 Decadal Survey.
Prusti, Timo, Gaudi, Bernard, Clarke, John, Somerville, Rachel, Kasdin, Jeremy, Marois, Christian, Rogers, Leslie, Kiessling, Alina, Gaudi, B. Scott, Turnbull, Margaret, Tamura, Motohide, Still, Martin, Seager, Sara, Quirrenbach, Andreas, Kuan, Gary, Mennesson, Bertrand, Feinberg, Lee, Warfield, Keith, Stark, Christopher, Stern, Daniel, Scowen, Paul, Cahoy, Kerri, Domagal-Goldman, shawn, Robinson, Tyler, Booth, Jeffrey, Mawet, Dimitri, Mouillet, David, Stapelfeldt, Karl, Guyon, Olivier   +28 more
core   +1 more source