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Related papers: A search for H2 around pre-main-sequence stars

200 papers

We present Very Large Array observations of the intermediate mass pre-main-sequence stars UX Ori and CQ Tau at 7mm, 3.6cm, and 6cm. These stars are members of the UX Ori variability class, where the origin of optical variability is thought…

Astrophysics · Physics 2009-11-06 L. Testi , A. Natta , D. S. Shepherd , D. J. Wilner

The UVS instrument on the Juno mission records far-ultraviolet reflected sunlight from Jupiter. These spectra are sensitive to the abundances of chemical species in the upper atmosphere and to the distribution of the stratospheric haze…

We describe results from a survey for J=3-2 12CO emission from visible stars with an infrared excess. The line is clearly detected in 21 objects, with molecular gas (>10^-3 Jupiter masses) common in targets with infrared excesses >0.01…

Astrophysics · Physics 2009-11-10 W. R. F. Dent , J. S. Greaves , I. M. Coulson

The sulfur abundance is poorly known in most environments. Yet, deriving the sulfur abundance is key to understanding the evolution of the chemistry from molecular clouds to planetary atmospheres. We present observations of H$_2$S 110-101…

Aim: The late stages of stellar evolution are mainly governed by the mass of the stars. Low- and intermediate-mass stars lose copious amounts of mass during the asymptotic giant branch (AGB) which obscure the central star making it…

We report on spectro-imaging observations of the Herbig-Haro 2 outflow with the ISOCAM camera onboard the Infrared Space Observatory (ISO). The [Ne II}] 12.81 microns and [Ne III]15.55 microns lines are detected only towards the jet working…

Astrophysics · Physics 2009-11-07 B. Lefloch , J. Cernicharo , S. Cabrit , A. Noriega-Crespo , A. Moro-Martin , D. Cesarsky

We investigated an isolated, globule-shaped object (0.37x0.11 pc), located near the centre of the Cygnus OB2 cluster and named proplyd #7 in optical observations. The source can be a massive star (with or without disc) with a HII region or…

FUSE ultraviolet spectra of 8 giant and supergiant stars reveal that high temperature (3 X 10^5 K) atmospheres are common in luminous cool stars and extend across the color-magnitude diagram from Alpha Car (F0 II) to the cool giant Alpha…

Astrophysics · Physics 2009-11-10 A. K. Dupree , A. Lobel , P. R. Young , T. B. Ake , J. Linsky , S. Redfield

We analyze high-resolution UV spectra of a small sample of Herbig Ae/Be stars (HAEBES) in order to explore the origin of the $T\sim10^5$ K gas in these stars. The C IV 1548,1550 \AA\ line luminosities are compared to non--simultaneous…

Solar and Stellar Astrophysics · Physics 2016-07-20 P. Wilson Cauley , Christopher M. Johns-Krull

We report the discovery of 4 new H$_2$ jets in Mon R1 star-forming region on the images obtained with the 2.5-m telescope of the Caucasian Mountain Observatory of SAI MSU through the filter, centered on the H$_2$ 1-0 S(1) emission line.…

Solar and Stellar Astrophysics · Physics 2021-12-13 T. Yu. Magakian , A. M. Tatarnikov , T. A. Movsessian , H. R Andreasyan

Jets from young stellar objects provide insight into the workings of the beating heart at the centre of star forming cores. In some cases, multiple pulsed outflows are detected such as the atomic and molecular jets from a proposed binary…

Solar and Stellar Astrophysics · Physics 2020-01-08 Chris J. R. Lynch , Michael D. Smith , Simon C. O. Glover

We carried out a millimeter wavelength line survey between 79 and 356 GHz with the IRAM-30m telescope to investigate the physical and chemical properties of the molecular envelope of the oxygen-rich AGB star IK Tau. We analysed the…

There is a group of binary post-AGB stars that show a conspicuous NIR excess, usually assumed to arise from hot dust in very compact possibly rotating disks. These stars are surrounded by significantly fainter nebulae than the "standard",…

Astrophysics of Galaxies · Physics 2015-06-16 V. Bujarrabal , J. Alcolea , H. Van Winckel , M. Santander-Garcia , A. Castro-Carrizo

Disks in the 6 Myr old cluster eta Chamaeleontis were searched for emission from hot H2. Around the M3 star ECHAJ0843.3-7905 we detect circumstellar gas orbiting at ~2 AU. If the gas is UV-excited, the ro-vibrational line traces a hot gas…

Astrophysics · Physics 2008-11-26 Suzanne K. Ramsay Howat , Jane S. Greaves

Low- and intermediate-mass stars at the asymptotic giant branch (AGB) are known to be prevalent dust providers to galaxies. However, the mechanisms responsible for the formation and acceleration of dust in the cool extended atmospheres of…

Solar and Stellar Astrophysics · Physics 2019-08-28 Christian Adam , Keiichi Ohnaka

We have observed the IC1396W globule in a narrow band filter centred on the 1-0 S(1) line of molecular hydrogen and in the J, H, K' broad-band filters. Three molecular hydrogen outflows could be identified by means of H2 emission. The…

Astrophysics · Physics 2009-11-07 D. Froebrich , A. Scholz

We present high spectral-resolution optical spectra of 49 Herbig Ae/Be stars in a search for the [O I] 6300A line. The vast majority of the stars in our sample show narrow (FWHM < 100 km/s) emission lines, centered on the stellar radial…

Astrophysics · Physics 2009-10-26 B. Acke , M. E. van den Ancker , C. P. Dullemond

Aims. We aim to provide observational constraints on diffusion models that predict peculiar chemical abundances in the atmospheres of Am stars. We also intend to check if chemical peculiarities and slow rotation can be explained by the…

Astrophysics · Physics 2009-11-13 L. Fossati , S. Bagnulo , R. Monier , S. A. Khan , O. Kochukhov , J. Landstreet , G. Wade , W. Weiss

The ionized core in the Sgr B2 Main star-forming region was imaged using the Submillimeter Array archival data observed for the H26$\alpha$ line and continuum emission at 0.86 millimeter with an angular resolution 0.3\arcsec. Eight…

Solar and Stellar Astrophysics · Physics 2015-05-30 Jun-Hui Zhao , M. C. H. Wright

We have modeled self-consistently the density and temperature profiles of gas and dust in protoplanetary disks, taking into account irradiation from a central star. Making use of this physical structure, we have calculated the level…

Astrophysics · Physics 2009-11-11 H. Nomura , T. J. Millar