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Hubble Space Telescope Imaging of the BL Lacertae Object OJ 287
Yanny, Brian; Jannuzi, Buell T.; Impey, Chris
Hubble Space Telescope WFPC-2 I-band (F814W) images of the BL Lacertae object OJ 287 and the surrounding field are presented. We find evidence of associated extended nebulosity near OJ 287, as well as a small nebulosity to the west, which may be spatially coincident with the position of previously observed radio emission. The brightness of a host …
Angular sizes of the faint blue galaxies
Im, M.; Griffiths, R. E.; Roche, N. +1 more
We investigate the angular sizes, morphologies and B-I colours of the 21≮I≮24 galaxies imaged on 10 Wide Field Planetary Camera fields. The number of galaxies with bluer colours (B-I<2.0) and moderately large angular sizes exceeds non-evolving predictions by a factor of ~2, but is consistent with pure L* evolution (PLE) models. There is also an…
Faint ultraviolet objects in the core of M13: optical counterparts of the low-luminosity X-ray source?
Ferraro, Francesco R.; Paltrinieri, Barbara; Fusi Pecci, Flavio +2 more
The core of the Galactic globular cluster M13 (NGC 6205) has been observed with WFPC2 on the Hubble Space Telescope through visual, blue, and mid- and far-UV filters in a programme devoted to studying the UV population in a sample of Galactic globular clusters. In the UV colour-magnitude diagrams derived from the HST images we have discovered thre…
Compressive character of low frequency waves driven by newborn ions at comet Grigg-Skjellerup
Coates, A. J.; Belmont, G.; Neubauer, F. M. +2 more
The investigation by Giotto of the environment of comet P/Grigg-Skjellerup has provided a large set of observations on cometary low-frequency waves for a weakly active comet, after the observations at comets P/Giacobini-Zinner and P/Halley. A large amount of waves are observed at frequencies close to the local water group ion cyclotron frequencies…
Vertical Structure of Jupiter's Atmosphere at the Galileo Probe Entry Latitude
Beebe, R. F.; Chanover, N. J.; Kuehn, D. M.
The vertical structure of Jupiter's atmosphere is examined to better characterize the latitudinal region of the Galileo probe entry site: +5°-10° planetographic latitude. One-hundred Hubble Space Telescope images of Jupiter taken with the 893- and 953-nm filters on 13 and 17 February 1995, 5 October 1995, and 14 May 1996 are analyzed, and a two-cl…
Solar wind proton flux latitudinal variations: Comparison between Ulysses in situ data and indirect measurements from interstellar Lyman α mapping
Lallement, Rosine; Quémerais, Eric; Summanen, Tuula
We compare the solar wind proton flux latitude dependence derived in the past from the interstellar neutral H distribution in the inner heliosphere from Lyman α observations with recent ``in situ'' solar wind observations by Ulysses [Goldstein et al., 1995, Phillips et al., 1995, 1996, J. L. Phillips, private communication, 1996]. We find common f…
Polarization sensitivity of the SUMER instrument on SOHO
Lemaire, P.; Hassler, D. M.; Longval, Y.
A Self-consistent Photoionization-Dust Continuum-Molecular Line Transfer Model of NGC 7027
Volk, Kevin; Kwok, Sun
A model to simulate the entire spectrum (1000 Å to 1 cm) of the high-excitation young planetary nebula NGC 7027 is presented. The ionized, dust, and molecular components of the object are modeled using geometric parameters obtained from visible, radio, infrared, and CO data. The physical processes considered include recombination lines of H and He…
Non-spherical source-surface model of the heliosphere: a scalar formulation
Schulz, M.
The source-surface method offers an alternative to full MHD simulation of the heliosphere. It entails specification of a surface from which the solar wind flows normally outward along straight lines. Compatibility with MHD results requires this (source) surface to be non-spherical in general and prolate (aligned with the solar dipole axis) in prot…
High Dynamic Range VLA Observations of the Gravitationally Lensed Quasar 0957+561
Stocke, John T.; Morse, Jon A.; Harvanek, Michael +1 more
We present 2, 3.6, 6, and 20 cm radio maps of the gravitationally leased quasar 0957+561 obtained with the VLA in A configuration. Besides the well-known jet and lobe structure associated with image A and the point sources associated with image B and the radio source G, the new 3.6 cm maps show interesting extensions of radio source G towards and …