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The Inner Nebula and Central Binary of the Symbiotic Star HM Sagittae
DOI: 10.1086/320086 Bibcode: 2001ApJ...551..512E

Davis, R. J.; Eyres, S. P. S.; Bode, M. F. +2 more

We present contemporaneous Hubble Space Telescope Wide Field Planetary Camera 2 and Very Large Array observations of the symbiotic nova HM Sge. We identify a number of discreet features at spatial scales smaller than ~0.1" embedded in the extended nebula, with radio and optical emission well correlated in the inner 1". For the first time we measur…

2001 The Astrophysical Journal
eHST 20
WIYN Open Cluster Study. VII. NGC 2451A and the Hipparcos Distance Scale
DOI: 10.1086/322118 Bibcode: 2001AJ....122.1486P

Deliyannis, Constantine P.; Kozhurina-Platais, Vera; Girard, Terrence M. +5 more

We provide new evidence that NGC 2451A is undoubtedly a young open cluster, although sparsely populated. New cluster membership has been derived from relative proper motions of 5868 stars. In total, 136 stars down to V~15 have membership probability Pµ>=2%. New CCD BV photometry indicates that about 70 stars are indeed main-seq…

2001 The Astronomical Journal
Hipparcos 20
Observed and Predicted Ratios of the Horizontal and Vertical Components of the Solar p-Mode Velocity Eigenfunctions
DOI: 10.1086/323260 Bibcode: 2001ApJ...561.1127R

Kosovichev, Alexander G.; Schou, Jesper; Rhodes, Edward J., Jr. +2 more

We present evidence that the observed ratios of the horizontal and vertical components of the solar intermediate-degree p-mode velocity eigenfunctions closely match theoretical predictions of these ratios. This evidence comes from estimates of the observed eigenfunction component ratios that were obtained from the fitting of the p-mode oscillation…

2001 The Astrophysical Journal
SOHO 20
Cosmic Ray Modulation over the Poles at Solar Maximum: Observations
DOI: 10.1023/A:1011889319933 Bibcode: 2001SSRv...97..309H

Heber, B.; Marsden, R. G.

Our knowledge of how galactic and anomalous cosmic rays are modulated in the inner heliosphere has been dramatically enlarged as a result of measurements from several missions launched in the past ten years. Among them, Ulysses explored the polar regions of the inner heliosphere during the last solar minimum period and is now revisiting southern p…

2001 Space Science Reviews
Ulysses 19
Discovery of pulsations from the Be/X-ray binary RXJ0101.3-7211 in the SMC by XMM-Newton
DOI: 10.1051/0004-6361:20010271 Bibcode: 2001A&A...369L..29S

Pietsch, W.; Haberl, F.; Sasaki, M. +1 more

We report pulsations in the X-ray flux of RX J0101.3-7211 in the Small Magellanic Cloud (SMC) with a period of (455+/-2) s in XMM-Newton EPIC-PN data. The X-ray spectrum can be described by a power-law with a photon index of 0.6+/-0.1. Timing analysis of ROSAT PSPC and HRI archival data confirms the pulsations and indicates a pe…

2001 Astronomy and Astrophysics
XMM-Newton 19
Compact Star Clusters in M81. II. Two Populations
DOI: 10.1086/322128 Bibcode: 2001AJ....122.1342C

Chandar, Rupali; Ford, Holland C.; Tsvetanov, Zlatan

We present the color and magnitude distributions of compact star clusters discovered in the early-type spiral galaxy M81, from Hubble Space Telescope Wide Field Planetary Camera 2 B, V, and I-band imaging. These clearly show the presence of two cluster populations-a typical red globular cluster system, as well as a young population, which was not …

2001 The Astronomical Journal
eHST 19
Solar wind plasma parameters on Ulysses: Detailed comparison between the URAP and SWOOPS experiments
DOI: 10.1029/2000JA000412 Bibcode: 2001JGR...10615665I

McComas, D. J.; Issautier, Karine; Gosling, J. T. +2 more

The presence of several instruments measuring plasma parameters aboard Ulysses made possible an extensive comparison between them. In this paper, we focus on solar wind electron parameters measured by the Unified RAdio and Plasma (URAP) wave receiver, using the thermal noise spectroscopy method, and by the Solar Wind Observations Over the Poles of…

2001 Journal of Geophysical Research
Ulysses 19
The Location of the Nucleus and the Morphology of Emission-Line Regions in NGC 1068
DOI: 10.1086/323637 Bibcode: 2001ApJ...558L..97T

Chary, Ranga-Ram; Thompson, Rodger I.; Corbin, Michael R. +1 more

This Letter presents new Near-Infrared Camera and Multi-Object Spectrometer data on the location of the nucleus and the morphology of hydrogen and [Si VI] emission in NGC 1068. The peak of the emission at 2.2 µm is a strong point source that marks the location of the nucleus. The [Si VI] line emission region consists of two main components, …

2001 The Astrophysical Journal
eHST 19
Molecular Gas and Star Formation in NGC 3077
DOI: 10.1086/323136 Bibcode: 2001AJ....122.1770M

Meier, David S.; Turner, Jean L.; Beck, Sara C.

We present high-resolution (~2.5") CO(1-0) and CO(2-1) images of the central 1 kpc of NGC 3077 made with the Owens Valley Millimeter Array. CO emission is distributed in three major complexes, which resolve into at least seven giant molecular clouds (GMCs). Two complexes are associated with the central starburst. A third, more distant complex is n…

2001 The Astronomical Journal
eHST 19
Variable Ultraviolet Absorption in the Spectrum of MR 2251-178
DOI: 10.1086/322870 Bibcode: 2001ApJ...556L...7G

Charlton, Jane C.; Eracleous, Michael; Ganguly, Rajib

We present an ultraviolet spectrum of MR 2251-178 taken with Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph (STIS) with the G230L grating. The observation is part of a snapshot program of quasars (QSOs) that systematically searches for intrinsic absorption lines through variability. The sample consists of all QSOs observed with …

2001 The Astrophysical Journal
eHST 19