Science Archives Publication System

Evidence for a Very Young Age of F Stars with Extrasolar Planets

DOI: 10.1086/319180 Bibcode: 2001ApJ...549L.237S

Schultz, A. B.; Suchkov, A. A.

We assess the age of nine planet-bearing (PB) F stars by comparing their metallicity, Hp variability, brightness anomaly, and location in the color-magnitude diagram with the same parameters for the Hyades and field F stars. Combined evidence from these parameters suggests that the age of our PB F stars is not very much different from the age of t…

2001 • The Astrophysical Journal

Hipparcos 15

Detection of H₂ Emission from Mira B in Ultraviolet Spectra from the Hubble Space Telescope

DOI: 10.1086/322871 Bibcode: 2001ApJ...556L..51W

Wood, Brian E.; Karovska, Margarita; Hack, Warren

We present ultraviolet spectra of Mira's companion star from the Space Telescope Imaging Spectrograph (STIS) instrument on board the Hubble Space Telescope (HST). The companion is generally assumed to be a white dwarf surrounded by an accretion disk fed by Mira's wind, which dominates the UV emission from the system. The STIS UV spectrum is domina…

2001 • The Astrophysical Journal

IUE eHST 15

The Physics of the Solar Lower Transition Region

DOI: 10.1086/322771 Bibcode: 2001ApJ...560..420D

Doschek, G. A.; Mariska, J. T.

We discuss quiet-Sun intensities of spectral lines of O IV λ1401.16 and Si IV λ1402.77, their ratio, and their relation to expected properties of the lower solar transition region. The data consist of simultaneous measurements of the two line intensities for 16,988 pixels with spatial dimensions of 1" square obtained by the Solar Ultraviolet Measu…

2001 • The Astrophysical Journal

SOHO 15

Young Clusters in the Magellanic Clouds. II.

DOI: 10.1086/318741 Bibcode: 2001AJ....121..905K

Da Costa, G. S.; Bessell, M. S.; Keller, Stefan C.

We present the results of a quantitative study of the degree of extension to the boundary of the classical convective core within intermediate-mass stars. The basis of our empirical study is the stellar population of four young populous clusters in the Magellanic Clouds that has recently been detailed by Keller, Bessell, & Da Costa. The sample…

2001 • The Astronomical Journal

eHST 15

Global Asymmetry of the Sun Observed in the Extreme Ultraviolet Radiation

DOI: 10.1023/A:1010369912487 Bibcode: 2001SoPh..201...27V

Zhukov, A. N.; Hochedez, J. F.; Veselovsky, I. S. +4 more

We report on observations of the solar luminosity variations in the Fe xii line (195 Å) over the period 1996-1999, which corresponds to the minimum and rising phase of the current 23rd solar cycle. The relatively or rather high temporal cadence and spatial resolution of the Extreme-ultraviolet Imaging Telescope (EIT) on board the Solar and Heliosp…

2001 • Solar Physics

SOHO 15

Gas cooling within the diffuse ISM of late-type galaxies

DOI: 10.1051/0004-6361:20010671 Bibcode: 2001A&A...373..827P

Boselli, A.; Völk, H. J.; Lequeux, J. +2 more

We combine observations of spiral galaxies in the [CII] line at 158 mu m, made with the Long Wavelength Spectrometer aboard ISO, with previous data from the Kuiper Airborne Observatory to study the origin of this line, which is the main coolant of the interstellar medium at relatively low temperatures. We also use HI and CO(1-0) observations of th…

2001 • Astronomy and Astrophysics

ISO 15

Detection of magnetic dipole lines of Fexii in the ultraviolet spectrum of the dwarf star ɛ Eri

DOI: 10.1046/j.1365-8711.2001.04360.x Bibcode: 2001MNRAS.322L...5J

McMurry, A. D.; Jordan, C.; Sim, S. A. +1 more

We report observations of the dwarf star ɛ Eri (K2V) made with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope. The high sensitivity of the STIS instrument has allowed us to detect the magnetic dipole transitions of Fexii at 1242.00 and 1349.38Å for the first time in a star other than the Sun. The width of the stronge…

2001 • Monthly Notices of the Royal Astronomical Society

eHST 15

A Critical Examination of Hypernova Remnant Candidates in M101. I. MF 83

DOI: 10.1086/318420 Bibcode: 2001ApJ...547..754L

Grebel, Eva K.; Lai, Shih-Ping; Ciardullo, Robin +2 more

The supernova remnant (SNR) candidate MF 83 in M101 is coincident with a very luminous X-ray source. Based on the high X-ray luminosity, it has been suggested that MF 83 is a ``hypernova remnant'' requiring an explosion energy about 2 orders of magnitude higher than normal supernovae. We have analyzed high-quality ground-based and Hubble Space Tel…

2001 • The Astrophysical Journal

eHST 15

Infrared Space Observatory Short Wavelength Spectrometer Observations of V1425 Aquilae (Nova Aquila 1995)

DOI: 10.1086/324100 Bibcode: 2001AJ....122.3305L

Morisset, C.; Humphreys, R. M.; Gehrz, R. D. +19 more

We present observations of the classical nova V1425 Aquilae (Nova Aquila 1995) with the Infrared Space Observatory's (ISO) Short Wavelength Spectrometer, the Isaac Newton Telescope's Intermediate Dispersion Spectrograph, and the International Ultraviolet Explorer's Short-Wavelength Primary Spectrograph. Analysis of He II (1640 Å) development const…

2001 • The Astronomical Journal

ISO IUE 15

A relation between dynamics of coronal mass ejections and production of solar energetic particles

DOI: 10.1051/0004-6361:20010241 Bibcode: 2001A&A...370.1064K

St. Cyr, O. C.; Torsti, J.; Kocharov, L. +1 more

During January 1997-June 1998, the Large Angle Spectroscopic Coronagraph (LASCO) aboard the Solar and Heliospheric Observatory spacecraft (SOHO) registered 670 coronal mass ejections (CMEs). We compare two groups of the 300-800 km s^-1 CMEs: (i) (very) gradually accelerating CMEs with acceleration below 10;m;s^-2, and (ii) impu…

2001 • Astronomy and Astrophysics

SOHO 15