Science Archives Publication System

Cool White Dwarfs in Cataclysmic Variables: Hubble Space Telescope Results on EG Cancri and HV Virginis

DOI: 10.1086/341116 Bibcode: 2002ApJ...574..950S

Szkody, Paula; Howell, Steve B.; Sion, Edward M. +1 more

Our Hubble Space Telescope (HST) ultraviolet spectra of the low mass transfer rate cataclysmic variables EG Cnc and HV Vir at 4 yr and 8 yr past their last superoutburst have shown that the white dwarfs in these systems are among the coolest yet observed in disk-accreting close binaries. The UV-optical fluxes of EG Cnc are consistent with a 11,700…

2002 • The Astrophysical Journal

eHST 26

Formation of the Three-Ring Structure Around Supernova 1987A

DOI: 10.1126/science.1069425 Bibcode: 2002Sci...296..321T

Tanaka, T.; Washimi, H.

From a magnetohydrodynamic simulation, we reproduce a three-ring structure in the circumstellar space of the supernova (SN) 1987A observed by the Hubble Space Telescope. When a star develops from a red supergiant (RSG) to a blue supergiant (BSG) just before the SN explosion, a wind-wind interaction occurs between the slow stellar wind from the RSG…

2002 • Science

eHST 26

Is There a 1998bw-like Supernova in the Afterglow of Gamma-Ray Burst 011121?

DOI: 10.1086/341749 Bibcode: 2002ApJ...572L.143D

Dar, Arnon; Dado, Shlomo; De Rújula, A.

We use the very simple and successful cannonball model of gamma-ray bursts (GRBs) and their afterglows (AGs) to analyze the observations of the strongly extinct optical AG of the relatively nearby GRB 011121; these observations were made with ground-based telescopes at early times and with the Hubble Space Telescope at later times. We show that GR…

2002 • The Astrophysical Journal

eHST 26

A Proper-Motion Survey for White Dwarfs with the Wide Field Planetary Camera 2

DOI: 10.1086/340759 Bibcode: 2002ApJ...573..644N

Alcock, C.; Axelrod, T. S.; Cook, K. H. +2 more

We have performed a search for halo white dwarfs as high proper motion objects in a second-epoch Wide Field Planetary Camera 2 image of the Groth-Westphal strip. The survey covers 74.8 arcmin² and is complete to V~26.5. We identify 24 high proper motion objects with µ>0.014" yr^-1. Five of these high proper motion obj…

2002 • The Astrophysical Journal

eHST 26

Detection of Two Binary Trans-Neptunian Objects, 1997 CQ₂₉ and 2000 CF₁₀₅, with the Hubble Space Telescope

DOI: 10.1086/344762 Bibcode: 2002AJ....124.3424N

Buie, Marc W.; Noll, Keith S.; Stephens, Denise C. +6 more

Images of the trans-Neptunian objects 1997 CQ₂₉ and 2000 CF₁₀₅ obtained with the Hubble Space Telescope WFPC2 camera show them to be binary. The two components of 1997 CQ₂₉ were separated in our images by 0.20"+/-0.03" in 2001 November and by 0.33"+/-0.01" in 2002 June/July. The corresponding minimum physical dista…

2002 • The Astronomical Journal

eHST 26

Sungrazing Comets: Properties of Nuclei and in Situ Detectability of Cometary Ions at 1 AU

DOI: 10.1006/icar.2001.6722 Bibcode: 2002Icar..155..350I

Bochsler, P.; Küppers, M.; Benz, W. +1 more

A one-dimensional sublimation model for cometary nuclei is used to derive size limits for the nuclei of sungrazing comets and to estimate oxygen ion fluxes at 1 AU from their evaporation. Given that none of the ≈300 sungrazers detected by the SOlar and Heliospheric Observatory (SOHO) was observed after disappearing behind the sun, and that small n…

2002 • Icarus

SOHO 25

BL Lac identification for the ultraluminous X-ray source observed in the direction of NGC 4698

DOI: 10.1051/0004-6361:20021391 Bibcode: 2002A&A...396..787F

Palazzi, E.; Cappi, M.; Martini, P. +11 more

We report the identification of the optical and radio counterparts of the ultraluminous X-ray (ULX) source XMMU J124825.9+083020 (NGC 4698-ULX1). The optical spectrum taken with the VLT yields a redshift of z=0.43, which implies that the ULX is not associated with the nearby galaxy NGC 4698. The spectral energy distribution calculated from the ava…

2002 • Astronomy and Astrophysics

XMM-Newton eHST 25

Observations of Core Fallback during Coronal Mass Ejections

DOI: 10.1086/338757 Bibcode: 2002ApJ...567.1211W

Sheeley, N. R., Jr.; Wang, Y. -M.

White-light observations made with the Large Angle and Spectrometric Coronagraph (LASCO) during the present solar maximum have revealed a multitude of faint, inward-moving features at heliocentric distances of r~2-6 R_solar. Most of these structures appear to originate above r~3 R_solar and may be signatures of the closing-down…

2002 • The Astrophysical Journal

SOHO 25

Solar Subsurface Flow Inferred Directly from Frequency-Wavenumber Correlations in the Seismic Velocity Field

DOI: 10.1086/324546 Bibcode: 2002ApJ...565..634W

Woodard, M. F.

We describe a general strategy for inverting helioseismic data for laterally inhomogeneous (aspherical) structure, in which the physical state of the solar interior is compared directly with inhomogeneity-induced correlations in the observable seismic wave field. The method was used to invert for subsurface supergranular-scale flow using Solar and…

2002 • The Astrophysical Journal

SOHO 25

Exploring the spectral properties of faint hard X-ray sources with XMM-Newton

DOI: 10.1051/0004-6361:20021235 Bibcode: 2002A&A...394..835P

Fiore, F.; Cappi, M.; Piconcelli, E. +3 more

We present a spectroscopic study of 41 hard X-ray sources detected serendipitously with high significance (>5sigma in the 2-10 keV band) in seven EPIC performance/verification phase observations. The large collecting area of EPIC allows us to explore the spectral properties of these faint hard X-ray sources with 2 < F_2-10 < 80 …

2002 • Astronomy and Astrophysics

XMM-Newton 25