Related papers: M-type Vega-like stars
(abridged) We present new 10-micron photometry of 21 nearby young stars obtained at the Palomar 5-meter and at the Keck I 10-meter telescopes as part of a program to search for dust in the habitable zone of young stars. Thirteen of the…
Optical linear polarization measurements are presented for about 30 Vega-like stars. These are then compared with the polarization observed for normal field stars. A significant fraction of the Vega-like stars are found to show polarization…
In this paper we present a catalog which includes 141 bright candidates ($\leq10.27$ mag, V band) showing the infrared (IR) excess at 22 $\mu$m. Of which, 38 stars are known IR excess stars or disk, 23 stars are double or multiple stars and…
As part of a large Spitzer/MIPS GTO program, we have searched for infrared excesses due to debris disks toward 26 FGK field stars known from radial velocity (RV) studies to have one or more planets. While none of these stars show excesses…
We investigate the nature of the mid-IR excess for 31 intermediate-mass stars that exhibit an 8 micron excess in either the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire or the Mid-Course Space Experiment using high resolution…
We have identified 230 Tycho-2 Spectral Catalog stars that exhibit 8 micron mid-infrared extraphotospheric excesses in the MidCourse Space Experiment (MSX) and Spitzer Space Telescope Galactic Legacy MidPlane Survey Extraordinaire (GLIMPSE)…
We have estimated the ages of a sample of A-type Vega-like stars by using Str\"{o}mgren \emph{uvby$\beta} photometric data and theoretical evolutionary tracks. We find that 13 percent of these A stars have been reported as Vega-like stars…
We report observations from the Spitzer Space Telescope (SST) regarding the frequency of 24 micron excess emission toward sun-like stars. Our unbiased sample is comprised of 309 stars with masses 0.7-2.2 Msun and ages from <3 Myr to >3 Gyr…
We present results of the analysis of a sample of 22 stars of spectral types from O7 to B5 and luminosity classes I-V for which Spitzer/IRS spectra are available. The IRS spectra of these stars are examined for signs of excess infrared (IR)…
Most Vega-like stars have far-infrared excess (60micron or longward in IRAS, ISO, or Spitzer MIPS bands) and contain cold dust (<~150K) analogous to the Sun's Kuiper-Belt region. However, dust in a region more akin to our asteroid belt and…
An analysis of low resolution spectra and infared data of 29 ISOGAL-DENIS sources with mid-IR excess is presented. Eight ISOGAL sources from our sample with 7-15 micron excess are found to be B and A-type stars, some of them with emission…
Stars of all evolutionary phases have been found to have excess infrared emission due to the presence of circumstellar material. To identify such stars, we have positionally correlated the infrared MSX point source catalogue and the Tycho 2…
We study the time dependency of Vega-like excesses using infrared studies obtained with the imaging photopolarimeter ISOPHOT on board of ISO. We review the different studies published on this issue, and critically check and revise ages and…
Various theoretical models predict the existence of extended $\gamma$-ray halo around normal galaxies that could be produced by interactions of cosmic rays with the circumgalactic medium or by annihilation or decay of hypothetical dark…
We have identified 17 A-type stars in the Galactic Plane that have mid-IR excesses at 8 micron. From the observed colors in the (r'-H_alpha)-(r'-i') plane, we first identified 23050 early A-type main sequence (MS) star candidates in the…
We present the result of a highly sensitive spectropolarimetric study dedicated to intermediate mass stars. We report the detection of sub-gauss surface magnetic fields on the normal, rapidly-rotating A-type star Vega and on the…
We present an analysis of ultraviolet (UV) emission in the outer regions of a local, volume-limited sample of 56 early-type galaxies, where H{\alpha} emission from massive star formation is typically absent. We find excess faint NUV…
In 2006 Vega was discovered to display excess near-infrared emission. Surveys now detect this phenomenon for one fifth of main-sequence stars, across various spectral types and ages. The excesses are interpreted as populations of small, hot…
We carry out an analysis of the Mg II 2796.34 A emission line in RS CVn stars and make a comparison with the normal stars studied in a previous paper (Paper I). The sample of RS CVn stars consists of 34 objects with known HIPPARCOS…
We report the results of a spectroscopic search for debris disks surrounding 41 nearby solar type stars, including 8 planet-bearing stars, using the {\it Spitzer Space Telescope}. With accurate relative photometry using the Infrared…