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Optical and EUV observations of solar flare kernels
Doyle, J. G.; Madjarska, M. S.; Butler, C. J. +3 more
We present high-resolution spectral observations, covering the entire optical region (3800-9000 Å), of a solar flare observed during a multi-wavelength campaign. The flare, recorded on 2002 January 11, was a medium solar flare event (GOES class C7.5). The spectral observations were carried out using the Hamilton echelle spectrograph on the coudé a…
A remarkable double helix in the V838 Mon nebula
Carlqvist, P.
In the beginning of 2002 the previously unnoted star V838 Mon had a powerful outburst. The star is surrounded by pre-existing, dusty clouds which are illuminated by the star in an expanding, parabolic layer. Spectacular images captured by the Hubble Space Telescope Advanced Camera for Surveys show that the clouds are to a great extent built up by …
HST/FOS time-resolved spectral mapping of IP Pegasi at the end of an outburst
Horne, K.; Saito, R. K.; Baptista, R.
We report an eclipse mapping analysis of time-resolved ultraviolet spectroscopy covering three eclipses of the dwarf nova IP Pegasi on the late decline of the 1993 May outburst. The eclipse maps of the first run show evidence of one spiral arm, suggesting that spiral structures may still be present in the accretion disc 9 days after the onset of t…
The evolutionary status of the bright high-latitude supergiant HD 190390
Cuypers, J.; Reyniers, M.
Despite its mean apparent magnitude of mV = 6.39, the evolutionary status of
The Jacobi constant for a cometary orbiter
Mysen, E.; Aksnes, K.
The Jacobi constant of a probe under the gravitational attraction of a rotating irregular body is rederived for excited, but free rigid rotation of the central mass. A related Tisserand-like quantity is found to be sufficiently conserved for it to qualify as a pseudo-integral. The quantity's near constancy is shown to imply that certain regions in…
Non-thermal processes associated with rising structures and waves during a "halo" type CME
Karlický, M.; Aurass, H.; Pohjolainen, S. +2 more
We analyse structures and events connected with a flare-associated "halo" type coronal mass ejection (CME) observed on December 18, 2000. A GOES C7.0 class X-ray flare started at 11:02 UT in NOAA Active Region 9269, located at N14 E03. Yohkoh SXT observed slowly rising soft X-ray loops already some 5 min before flare start. Hα images show a two-ri…
Coronal oscillations in the vicinity of a sunspot as observed by GIS/CDS
Foley, C. R.; Doyle, J. G.; Banerjee, D. +2 more
In this paper, we present results from a time series analysis of data from the Grazing Incidence Spectrometer (GIS), onboard SoHO. Our observations were concentrated at the boundary between the quiet Sun and an active region, close to a sunspot plume. The dominant oscillations in all the lines studied are of periods longer than 5 min. Although our…
Extended very cold dust in the interacting HI ring galaxy pair NGC 2293 / 2292
Krause, O.; Barnes, D.; Stickel, M.
The LGG 138 galaxy group members NGC 2292 and NGC 2293 were imaged with ISOPHOT in the far-infrared (FIR) at {60 µ m}, {100 µ m}, and {200 µ m}. While no FIR emission is seen at {60 µ m}, and only very low level emission is present at {100 µ m}, compact FIR emission from both NGC 2292 and NGC 2293 galaxy centres and e…
ISO observations of the interacting galaxy Markarian 297. with the powerful supernova remnant 1982aa
Hanlon, L.; McBreen, B.; Clavel, J. +10 more
Markarian (Mkn) 297 is a complex system comprised of two interacting galaxies that has been modelled with a variety of scenarios. Observations of this system were made with the Infrared Space Observatory (ISO) using the ISOCAM, ISOPHOT and LWS instruments. ISOCAM maps at 6.7 µm, 7.7 µm, 12 µm and 14.3 µm are presented which…
The absolute magnitude of K0V stars from Hipparcos data using an analytical treatment of the Malmquist bias
Butkevich, A. G.; Teerikorpi, P.; Berdyugin, A. V.
We calculate the average absolute magnitude for Hipparcos single K0V stars, using a theoretical curve for the distance-dependent Malmquist bias in the data. This method is shown to be well applicable to stellar data with good parallaxes and gives results in agreement with a previous study that used another treatment of the bias developed in extrag…