Search Publications

A Preliminary Study of Magnetosphere-Ionosphere-Thermosphere Coupling at Jupiter: Juno Multi-Instrument Measurements and Modeling Tools
DOI: 10.1029/2021JA029469 Bibcode: 2021JGRA..12629469W

Gérard, Jean-Claude; André, Nicolas; Louarn, Philippe +20 more

The dynamics of the Jovian magnetosphere are controlled by the interplay of the planet's fast rotation, its main iogenic plasma source and its interaction with the solar wind. Magnetosphere-Ionosphere-Thermosphere (MIT) coupling processes controlling this interplay are significantly different from their Earth and Saturn counterparts. At the ionosp…

2021 Journal of Geophysical Research (Space Physics)
eHST 16
Directly Determined Properties of HD 97658 from Interferometric Observations
DOI: 10.3847/1538-3881/ac141a Bibcode: 2021AJ....162..118E

Schaefer, Gail H.; Dragomir, Diana; von Braun, Kaspar +5 more

We conducted interferometric observations with the CHARA Array of transiting super-Earth host HD 97658 and measured its limb-darkened angular diameter to be θLD = 0.314 ± 0.004 mas. The combination of the angular diameter with the Gaia EDR3 parallax value with zero-point correction (π = 46.412 ± 0.022 mas, d =21.546 ± 0.011 pc) yields a…

2021 The Astronomical Journal
Gaia 16
AGN and star formation across cosmic time
DOI: 10.1093/mnras/stab598 Bibcode: 2021MNRAS.503.3992S

Page, M. J.; Symeonidis, M.

We investigate the balance of power between stars and AGN across cosmic history, based on the comparison between the infrared (IR) galaxy luminosity function (LF) and the IR AGN LF. The former corresponds to emission from dust heated by stars and AGN, whereas the latter includes emission from AGN-heated dust only. We find that at all redshifts (at…

2021 Monthly Notices of the Royal Astronomical Society
Herschel 16
A CHEOPS white dwarf transit search
DOI: 10.1051/0004-6361/202140913 Bibcode: 2021A&A...651L..12M

Lendl, Monika; Brandeker, Alexis; Heng, Kevin +2 more

White dwarf spectroscopy shows that nearly half of white dwarf atmospheres contain metals that must have been accreted from planetary material that survived the red giant phases of stellar evolution. We can use metal pollution in white dwarf atmospheres as flags, signalling recent accretion, in order to prioritize an efficient sample of white dwar…

2021 Astronomy and Astrophysics
CHEOPS 15
TESS-Keck Survey. V. Twin Sub-Neptunes Transiting the Nearby G Star HD 63935
DOI: 10.3847/1538-3881/ac18cb Bibcode: 2021AJ....162..215S

Batalha, Natalie M.; Latham, David W.; Mayo, Andrew W. +55 more

We present the discovery of two nearly identically sized sub-Neptune transiting planets orbiting HD 63935, a bright (V = 8.6 mag), Sun-like (Teff = 5560 K) star at 49 pc. TESS identified the first planet, HD 63935 b (TOI-509.01), in Sectors 7 and 34. We identified the second signal (HD 63935 c) in Keck High Resolution Echelle Spectromet…

2021 The Astronomical Journal
Gaia 15
The central region of the enigmatic Malin 1
DOI: 10.1007/s12036-021-09715-5 Bibcode: 2021JApA...42...59S

Saha, Kanak; Barway, Sudhanshu; Dhiwar, Suraj +2 more

Malin 1, being a class of giant low surface galaxies, continues to surprise us even today. The HST/F814W observation has shown that the central region of Malin 1 is more like a normal SB0/a galaxy, while the rest of the disk has the characteristic of a low surface brightness system. The AstroSat/UVIT observations suggest scattered recent star form…

2021 Journal of Astrophysics and Astronomy
eHST 15
S5: The Destruction of a Bright Dwarf Galaxy as Revealed by the Chemistry of the Indus Stellar Stream
DOI: 10.3847/1538-4357/abfc54 Bibcode: 2021ApJ...915..103H

Lewis, Geraint F.; Casey, Andrew R.; Erkal, Denis +14 more

The recently discovered Indus stellar stream exhibits a diverse chemical signature compared to what is found for most other streams due to the abundances of two outlier stars, Indus_0 and Indus_13. Indus_13 exhibits an extreme enhancement in rapid neutron-capture (r-)process elements with [Eu/Fe] = + 1.81. It thus provides direct evidence of the a…

2021 The Astrophysical Journal
Gaia 15
On the mechanism of polarized metre-wave stellar emission
DOI: 10.1093/mnras/staa3373 Bibcode: 2021MNRAS.500.3898V

Vedantham, H. K.

Two coherent radio emission mechanisms operate in stellar coronae: plasma emission and cyclotron emission. They directly probe the electron density and magnetic field strength respectively. Most stellar radio detections have been made at cm-wavelengths where it is often not possible to uniquely identify the emission mechanism, hindering the utilit…

2021 Monthly Notices of the Royal Astronomical Society
Gaia 15
The first coronal mass ejection observed in both visible-light and UV H I Ly-α channels of the Metis coronagraph on board Solar Orbiter
DOI: 10.1051/0004-6361/202142407 Bibcode: 2021A&A...656L..14A

Heinzel, P.; Vial, J. -C.; Woch, J. +68 more

Context. The Metis coronagraph on board Solar Orbiter offers a new view of coronal mass ejections (CMEs), observing them for the first time with simultaneous images acquired with a broad-band filter in the visible-light interval and with a narrow-band filter around the H I Ly-α line at 121.567 nm, the so-called Metis UV channel.
Aims: We show…

2021 Astronomy and Astrophysics
SOHO SolarOrbiter 15
Probing Jets from Young Embedded Sources: Clues from HST Near-IR [Fe II] Images
DOI: 10.3847/1538-4357/ac06c5 Bibcode: 2021ApJ...919...23E

Hartigan, Patrick; Giannini, Teresa; Nisini, Brunella +6 more

We present near-infrared [Fe II] images of four Class 0/I jets (HH 1/2, HH 34, HH 111, HH 46/47) observed with the Hubble Space Telescope (HST) Wide Field Camera 3. The unprecedented angular resolution allows us to measure proper motions, jet widths and trajectories, and extinction along the jets. In all cases, we detect the counterjet, which was …

2021 The Astrophysical Journal
eHST 15