Документ взят из кэша поисковой машины. Адрес
оригинального документа
: http://star.arm.ac.uk/annrep/annrep2003/node51.html
Дата изменения: Tue May 18 17:48:07 2004 Дата индексирования: Tue Oct 2 05:03:02 2012 Кодировка: Поисковые слова: п п п п п п п п п п п п п п п п |
In collaborative work with David García Alvarez (an Observatory PhD student now at Harvard) and John Butler, an extensive study of the RS CVn binary HR1099 was completed leading to two papers; the first on Doppler imaging and the second on flare activity.
Spectra for the Doppler imaging were taken at two different sites, Kitt
Peak National Observatory (KPNO), Arizona, and Mount Stromlo Observatory
(MSO), Australia, during the 1998 MUltiSIte COntinuous Spectroscopic
(MUSICOS) campaign. Contemporaneous photometry from the Wolfgang-Amadeus
Automatic Photoelectric Telescope (APT) at the Fairborn Observatory,
Tucson, Arizona, was used to constrain the Doppler images. The resulting
maximum entropy reconstructions based on the least-squares deconvolved
profiles, derived from 2000 photospheric absorption lines, reveal
the presence of starspots at medium-high latitudes. We have obtained maps
for both components of the binary system for the first time. The
predominant structure in the primary component is an off-centred polar
spot, confirming previous work on the same target by using independent
codes. The result is verified by using both data sets independently. The
lower spectral resolution data set gives a less detailed map for the MSO
data set. The images obtained for the secondary component show a
low-latitude spot around orbital phase 0.7. This spot seems to mirror the
structure seen on the primary. It might suggest that tidal forces may
influence the spot distribution on this binary system.
In the flare paper, simultaneous and continuous observations in
H, H
, HeI D3, the NaI D1D2 doublet and the CaII H & K lines were
obtained. As above, the spectroscopic observations were obtained during
the MUSICOS 1998 campaign involving several observatories and
instruments, both echelle and long-slit spectrographs. During this
campaign, HR1099 was observed almost continuously for more than 8 orbits
of 2.8 days. Two large optical flares were observed, both showing an
increase in the emission of H
, CaII H & K, H
and
HeI D3 and a strong filling-in of the NaI
D1,D2 doublet.
Contemporary photometric observations were carried out with the robotic
telescopes APT-80 of Catania and Phoenix-25 of Fairborn Observatories.
Maps of the distribution of the spotted regions on the photosphere of the
binary components were derived using the Maximum Entropy and Tikhonov
photometric regularization criteria. Rotational modulation was observed
in H and HeI D3 in anti-correlation with the
photometric light curves. Both flares occurred at the same binary phase
(0.85), suggesting that these events took place in the same active region.
Simultaneous X-ray observations, performed by ASM on board RXTE, show
several flare-like events, some of which correlate well with the observed
optical flares. Rotational modulation in the X-ray light curve has been
detected with minimum flux when the less active G5V star was in front. A
possible periodicity in the X-ray flare-like events was also found.