Science Archives Publication System

VLA Radio Positions of Stars: 1978-1995

DOI: 10.1086/375302 Bibcode: 2003AJ....125.3252J

Johnston, Kenneth; de Vegt, Christian; Gaume, Ralph

VLA astrometric positions of the radio emission from 52 stars are reported, from observations obtained between 1978 and 1995. The positions of these stars have been obtained and reduced in a uniform manner. Based on our measurements, the offset of the optical (Hipparcos) frame from the radio reference frame is in agreement with the Hipparcos extra…

2003 • The Astronomical Journal

Hipparcos 10

η Carinae: The optical flare-like events during low-excitation passages

DOI: 10.1051/0004-6361:20030688 Bibcode: 2003A&A...405.1057V

Sterken, C.; van Genderen, A. M.; Allen, W. H.

The 1992.5 and 1998.0 low-excitation events of the possible binary in the core of η Carinae show a conspicuous flare-like event in optical and near-ultraviolet light. These events last a couple of months and have a light amplitude of 0.1m-0.2m in V. Considering the presence of a dense (bi-polar) stellar wind, one explanation could be that some typ…

2003 • Astronomy and Astrophysics

eHST 10

Solar cycle dependence of interplanetary Lyman α emission and solar wind anisotropies derived from NOZOMI/UVS and SOHO/SWAN observations

DOI: 10.1029/2003JA009882 Bibcode: 2003JGRA..108.8035N

Bertaux, Jean-Loup; Lallement, Rosine; Taguchi, Makoto +5 more

We have investigated the distributions of neutral interplanetary hydrogen Lyman α emission and their solar cycle dependence from observations with the ultraviolet imaging spectrometer (UVS) onboard the NOZOMI spacecraft and the solar wind anisotropy instrument (SWAN) onboard the solar and heliospheric observatory (SOHO) spacecraft. The SOHO/SWAN o…

2003 • Journal of Geophysical Research (Space Physics)

SOHO 10

In-Orbit Vignetting Calibrations of XMM-Newton Telescopes

DOI: 10.1023/B:EXPA.0000036175.73391.71 Bibcode: 2003ExA....15...89L

Finoguenov, A.; Gondoin, P.; Aschenbach, B. +4 more

We describe measurements of the mirror vignetting in the XMM-Newton Observatory made in-orbit, using observations of SNR G21.5-09 and SNR 3C58 with the EPIC imaging cameras. The instrument features that complicate these measurements are briefly described. We show the spatial and energy dependences of measured vignetting, outlining assumptions made…

2003 • Experimental Astronomy

XMM-Newton 10

Anomalous Evolution of the Dwarf Galaxy HIPASS J1321-31

DOI: 10.1086/379157 Bibcode: 2003ApJ...596L..47P

Knezek, Patricia M.; Saha, A.; Freeman, Kenneth C. +6 more

We present Hubble Space Telescope/WFPC2 observations of the dwarf galaxy HIPASS J1321-31. This unusual galaxy lies in the direction of the Centaurus A group of galaxies and has a color-magnitude diagram with a distinctive red plume of luminous stars. This feature could arise from (1) a red giant branch if the galaxy were much nearer than previousl…

2003 • The Astrophysical Journal

eHST 10

Acoustic Wave Propagation in the Sun: Implications for Wave Field and Time-Distance Helioseismology

DOI: 10.1086/367757 Bibcode: 2003ApJ...582L.121T

Thompson, M. J.; Rajaguru, S. P.; Tong, C. H. +2 more

We present results of the numerical simulation of acoustic wave propagation in the Sun's subphotospheric layers. A finite-difference code is used to calculate the pressure perturbation in the frequency domain. We show that the oscillatory seismic signals are closely associated with the solar density and sound speed structures. Owing to the acousti…

2003 • The Astrophysical Journal

SOHO 10

Search for a chromospheric resonator above sunspots

DOI: 10.1016/S0273-1177(03)00312-0 Bibcode: 2003AdSpR..32.1097B

Kjeldseth-Moe, O.; Brekke, P.; Brynildsen, N. +2 more

We have recently observed thirteen sunspots, both with CDS on SOHO and TRACE. For each sunspot we investigate the oscillations in the chromosphere, transition region and corona. Above the umbra the power spectra show one dominant peak corresponding to a period of 3 minutes. The intensity oscillation amplitude increases with increasing temperature,…

2003 • Advances in Space Research

SOHO 10

Circumnuclear Structures in the Interacting Seyfert Galaxy NGC 1241: Kinematics and Optical/Infrared Morphology

DOI: 10.1086/381215 Bibcode: 2003ApJ...597..860D

Díaz, Rubén J.; Dottori, Horacio; Vera-Villamizar, Nelson +1 more

We studied the spiral pattern in the inner 6.5" (1^''=257 pc) central regions of the interacting active nucleus galaxy NGC 1241 using Gemini North Telescope high-resolution K_s- and J-band images and Hubble Space Telescope (HST) Paα and H- and (V+R)-band images with high resolution in the range from ~0.1" to ~0.3" along with in…

2003 • The Astrophysical Journal

eHST 10

Searching for Variable Stars in the Central Part of the Globular Cluster M22

DOI: 10.48550/arXiv.astro-ph/0401385 Bibcode: 2003AcA....53..371P

Pietrukowicz, P.; Kaluzny, J.

Time-series data taken with the Hubble Space Telescope of three fields covering the central part of the globular cluster M22 have been analyzed in search of variable objects. We report identification of eleven periodic variables of which eight are new discoveries. The sample includes five certain contact binaries as well as one SX Phe star. Two ob…

2003 • Acta Astronomica

eHST 10

Cosmic Gravitational Shear from the Hubble Space Telescope Medium Deep Survey

DOI: 10.1086/380814 Bibcode: 2003ApJ...598L..71C

Casertano, Stefano; Griffiths, Richard E.; Ratnatunga, Kavan U.

We present a measurement of cosmic shear on scales ranging from 10" to 2' in 347 Wide Field Planetary Camera 2 (WFPC2) images of random fields. Our result is based on shapes measured via image fitting and on a simple statistical technique; careful calibration of each step allows us to quantify our systematic uncertainties and to measure the cosmic…

2003 • The Astrophysical Journal

eHST 10