Science Archives Publication System

EUV Full-Sun Imaging and Pointing Calibration of the SOHO Coronal Diagnostic Spectrometer

DOI: 10.1023/A:1004915531252 Bibcode: 1998SoPh..178...71T

Thompson, William; Carter, Martin

Although the field of view of the Normal Incidence Spectrometer (NIS) of the Coronal Diagnostic Spectrometer (CDS) is 4×4 arc min, it is possible to observe the full solar disk by forming a mosaic of images taken in succession. This paper describes just such a study which has been used to collect images of the Sun simultaneously in six wavelengths…

1998 • Solar Physics

SOHO 6

Multi-Spacecraft Discontinuity Analysis: Orientation and Motion

Bibcode: 1998ISSIR...1..271D

Dunlop, Malcolm W.; Woodward, Timothy I.

1998 • ISSI Scientific Reports Series

Cluster 6

ISO's View on Massive Star Evolution: Neon Abundances in Wolf-Rayet Stars

DOI: 10.1023/A:1001172515987 Bibcode: 1998Ap&SS.255..157M

Willis, A. J.; Morris, P. W.; van der Hucht, K. A. +1 more

1998 • Astrophysics and Space Science

ISO 6

Investigation of the Small-Scale Temperature and Density Fluctuations in Planetary Nebulae through the Use of the ISO Data

DOI: 10.1023/A:1001544526291 Bibcode: 1998Ap&SS.255..513K

Kholtygin, A. F.

The problem of the ne and Te fluctuations in the planetary nebulae (PN) in a view of the ISO data was investigated. The fluxes in the OIII fine structure (FS) lines for a large sample of PNe were estimated.

1998 • Astrophysics and Space Science

ISO 6

Relative intensities of intercombination lines in ultraviolet spectra of T Tauri stars

Bibcode: 1998AstL...24..748L

Lamzin, S. A.; Gomez de Castro, A. I.

Using the accretion shock wave model (Lamzin 1998), we calculate the relative intensities of the strongest intercombination lines in the range 1200-2000 Angstroms. We make a qualitative comparison of theoretical spectra with IUE low-resolution (~=6 Angstroms) spectra of T Tauri stars. We predict that several intercombination lines can be identifie…

1998 • Astronomy Letters

IUE 6

An ISO view on interstellar dust heated by red giant stars

Bibcode: 1998A&A...335..287L

Epchtein, N.; Boulanger, F.; Lagache, G. +4 more

In order to study the structure and emission of the diffuse interstellar medium when it is heated by red giant stars, we have obtained ISOPHOT maps centered at proximity of a sample of such objects. The maps are 7'x7' with a pixel size of 45'', and were made at 60 and 90 mu m. Here we present the preliminary results of this program, based on data …

1998 • Astronomy and Astrophysics

ISO 6

Two serendipitous low-mass LMC clusters discovered with HST1

DOI: 10.1046/j.1365-8711.1998.01339.x Bibcode: 1998MNRAS.295..860S

Elson, Rebecca A. W.; Sigurdsson, Steinn; Gilmore, Gerard F. +1 more

We present V and I photometry of two open clusters in the LMC down to V~26. The clusters were imaged with the Wide Field and Planetary Camera 2 (WFPC2) on board the Hubble Space Telescope (HST), as part of the Medium Deep Survey Key Project. Both are low-luminosity (M_V~-3.5), low-mass (M~10^3 Msolar) systems. The chance discovery of these two clu…

1998 • Monthly Notices of the Royal Astronomical Society

eHST 6

Optimal Proper-Motion Measurements with the Wide Field and Planetary Camera

DOI: 10.1086/300588 Bibcode: 1998AJ....116.2569I

Lewis, Geraint F.; Ibata, Rodrigo A.

An optimal maximum-likelihood technique for computing point-source image centroids from many, slightly offset, CCD frames is presented. The method is especially useful for measuring stellar proper motions from data taken with the Wide Field and Planetary Camera on board the Hubble Space Telescope, and also provides a means to identify very compact…

1998 • The Astronomical Journal

eHST 6

CCD Positions for the Outer Planets in 1996-1997 Determined in the Extragalactic Reference Frame

DOI: 10.1086/300507 Bibcode: 1998AJ....116.1461S

Stone, Ronald C.

This paper presents 316 new equatorial positions for the planets Uranus, Neptune, and Pluto obtained in 1996-1997 with the Flagstaff Astrometric Scanning Transit Telescope (FASTT). All the positions were determined in the extragalactic reference frame using CCD observations and are accurate to ~+/-0.2" in each coordinate. When these positions are …

1998 • The Astronomical Journal

Hipparcos 6

Hubble Space Telescope Resolved Image and Spectra of the Z ~= 2 QSO 1345+584

DOI: 10.1086/300427 Bibcode: 1998AJ....116...20H

Hutchings, J. B.

QSO 1345+584 has been spatially resolved by direct images and in spectral images, and has asymmetrically extended flux to the west, where its inner radio structure is seen. The brightest knots in the resolved flux correspond closely with knots in the curved radio jet, and the brightest knot has a velocity of approach of some 3000 km s^-1 with resp…

1998 • The Astronomical Journal

eHST 6