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200 papers

Radio sources have traditionally provided convenient beacons for probing the early Universe. Hy Spinrad was among the first of the tenacious breed of observers who would attempt to obtain optical identifications and spectra of the faintest…

The James Webb Space Telescope (JWST) observations have revolutionized extragalactic research, particularly with the discovery of little red dots (LRD), which we propose are dust-reddened broad-line active galactic nuclei (AGNs). Their…

Astrophysics of Galaxies · Physics 2025-02-06 Zhengrong Li , Kohei Inayoshi , Kejian Chen , Kohei Ichikawa , Luis C. Ho

Extrasolar planets are expected to emit detectable low frequency radio emission. In this paper we present results from new low frequency observations of two extrasolar planetary systems (Epsilon Eridani and HD 128311) taken at 150 MHz with…

Astrophysics · Physics 2009-11-13 Samuel George , Ian Stevens

(Abridged) Aims: Systematic surveys to search for exoplanets have been mostly dedicated to solar-type stars sofar. We developed in 2004 a method to extend such searches to earlier A-F type dwarfs and started spectroscopic surveys to search…

Astrophysics · Physics 2009-11-13 A. -M. Lagrange , M. Desort , F. Galland , S. Udry , M. Mayor

Planet frequency shows a strong positive correlation with host mass from the hydrogen-burning limit to M ~ 2Msun. No search has yet been conducted for planets of higher-mass hosts because all existing techniques are insensitive to these…

Astrophysics · Physics 2009-11-13 Andrew Gould , Mukremin Kilic

We report the results of our HST snapshot survey with the ACS HRC PR200L prism, designed to measure the near-UV emission in a sample of nearby M dwarfs. 33 stars were observed, spanning the mass range from 0.1 - 0.6 solar masses (T_eff ~…

Astrophysics · Physics 2009-11-13 Lucianne M. Walkowicz , Christopher M. Johns-Krull , Suzanne L. Hawley

With the improvements in radio interferometry sensitivity, the quest for coherent radio emission from exoplanets and ultra-cool dwarfs, which is indicative of their magnetic fields, has gained significant momentum in recent years. We…

The RAdial Velocity Experiment (RAVE) is a spectroscopic survey of the Milky Way. We use the subsample of spectra with spectroscopically determined values of stellar parameters to determine the distances to these stars. The list currently…

Precise radial velocity (RV) measurements are a crucial tool for exoplanet discovery and characterization. Today, the majority of these measurements are derived from Echelle spectra in the optical wavelength region using cross-correlation…

We present the first systematic search for GHz frequency radio emission from directly imaged exoplanets using Very Large Array (VLA) observations of sufficient angular resolution to separate the planets from their host stars. We obtained…

Earth and Planetary Astrophysics · Physics 2021-12-22 Yvette Cendes , Peter K. G. Williams , Edo Berger

Recent studies of the stellar population in the solar neighborhood (<20 pc) suggest that there are undetected white dwarfs (WDs) in multiple systems with main sequence companions. Detecting these hidden stars and obtaining a more complete…

Solar and Stellar Astrophysics · Physics 2017-11-29 Ira Bar , Paul Vreeswijk , Avishay Gal-Yam , Eran O. Ofek , Gijs Nelemans

To investigate the radio properties of the recently found high-redshift population, we collected a sample of $919$ little red dots (LRDs) from the literature. By cross-matching their coordinates with the radio catalogues based on the first-…

Astrophysics of Galaxies · Physics 2024-12-25 K. Perger , J. Fogasy , S. Frey , K. É. Gabányi

Searches for planets around evolved G-K subgiant and giant stars are essential for developing general understanding of planet formation and evolution of the planetary systems. Precise radial velocity (RV) measurements of giants have lead to…

Astrophysics · Physics 2007-12-17 Grzegorz Nowak , Andrzej Niedzielski

Due to their low mass and luminosity, M dwarfs are ideal targets if one hopes to find low-mass planets similar to Earth by using the radial velocity (RV) method. However, stellar magnetic cycles could add noise or even mimic the RV signal…

Solar and Stellar Astrophysics · Physics 2015-06-04 J. Gomes da Silva , N. C. Santos , X. Bonfils , X. Delfosse , T. Forveille , S. Udry , X. Dumusque , C. Lovis

We present a Mass-Luminosity Relation (MLR) for red dwarfs spanning a range of masses from 0.62 Msun to the end of the stellar main sequence at 0.08 Msun. The relation is based on 47 stars for which dynamical masses have been determined,…

The Rapid Temporal Survey (RATS) explores the faint, variable sky. Our observations search a parameter space which, until now, has never been exploited from the ground. Our strategy involves observing the sky close to the Galactic plane…

Astrophysics of Galaxies · Physics 2015-05-27 Thomas Barclay , Gavin Ramsay , Pasi Hakala , Ralf Napiwotzki , Gijs Nelemans , Stephen Potter , Ian Todd

Up to now, most planet search projects have concentrated on F to K stars. In order to considerably widen the view, we have stated a survey for planets of old, nearby brown dwarfs and very low mass stars. Using UVES, we have observed 26…

Astrophysics · Physics 2011-05-23 Eike W. Guenther , Guenther Wuchterl

Small planets are common around late-M dwarfs and can be detected through highly precise photometry by the transit method. Planets orbiting nearby stars are particularly important as they are often the best-suited for future follow-up…

Context. One of the most important discoveries by the James Webb Space Telescope (JWST) is the unexpected existence in the Early Universe (z > 4) of very large quantities of "Little Red Dots" (LRDs), compact luminous red galaxies of…

Astrophysics of Galaxies · Physics 2026-03-18 L. F. Rodriguez , I. F. Mirabel

The high-redshift ($z>4$) compact sources with ``V-shaped" spectral energy distributions (SEDs), known as Little Red Dots (LRDs), are discovered by the James Webb Space Telescope and provide valuable clues to the physics of active galactic…

Astrophysics of Galaxies · Physics 2025-08-26 Shuying Zhou , Mouyuan Sun , Zijian Zhang , Jie Chen , Luis C. Ho