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W. J. Wagner R. M. E. Illing C. B. Sawyer L. L. House N. R. Sheeley Jr. R. A. Howard M. J. Koomen D. J. Michels R. N. Smartt M. Dryer 《Solar physics》1983,83(1):153-166
Multi-telescope observations of the coronal transient of 15–16 April, 1980 provide simultaneous data from the Solar Maximum Mission Coronagraph/Polarimeter, the Solwind Coronagraph, and the new Emission Line Coronagraph of the Sacramento Peak Observatory. An eruptive prominence-associated white light transient is for the first time seen as an unusual wave or brightening in Fe x
gl6374 (but not in Fe xiv
gl5303). Several interpretations of this fleeting enhancement are offered.The prominence shows a slowly increasing acceleration which peaks at the time of the Fe event. The white light loop transient surrounding the prominence expands at a well-documented constant speed to 10R
, with an extrapolated start time at zero height coincident with the surface activity.This loop transient exemplifies those seen above 1.7R
in that leading the disturbance is a bright (N
e-enhanced) loop rather than dark. This is consistent with a report of the behavior of another eruptive event observed by Fisher and Poland (1981) which began as a density depletion in the lower corona, with a bright loop forming at greater altitudes. The top of the bright loop ultimately fades in the outer corona while slow radial growth continues in the legs.The National Center for Atmospheric Research is sponsored by the National Science Foundation. 相似文献
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In this summary of the 10 November 2006 RAS Specialist Discussion Meeting, organizers Paul Crowther and Steve Smartt consider aspects of massive stellar evolution, their dependence upon stellar winds, progenitor models and explosion mechanisms. In addition, observations of core-collapse supernovae were discussed alongside the question of whether supernovae form significant quantities of dust, of relevance to the detection of dust in star-forming galaxies in the early universe. 相似文献
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A. Pastorello R. M. Quimby † S. J. Smartt S. Mattila H. Navasardyan R. M. Crockett N. Elias-Rosa P. Mondol J. C. Wheeler D. R. Young 《Monthly notices of the Royal Astronomical Society》2008,389(1):131-140
We present photometric and spectroscopic data of the peculiar SN 2005la, an object which shows an optical light curve with some luminosity fluctuations and spectra with comparably strong narrow hydrogen and helium lines, probably of circumstellar nature. The increasing full width at half-maximum velocity of these lines is indicative of an acceleration of the circumstellar material. SN 2005la exhibits hybrid properties, sharing some similarities with both Type IIn supernovae and 2006jc-like (Type Ibn) events. We propose that the progenitor of SN 2005la was a very young Wolf–Rayet (WN-type) star which experienced mass ejection episodes shortly before core collapse. 相似文献
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Stephen J. Smartt 《Astrophysics and Space Science》2002,281(1-2):187-190
The masses and the evolutionary states of the progenitors of core-collapse supernovae are not well constrained by direct observations.
Stellar evolution theory generally predicts that massive stars with initial masses less than about 30M⊙ should undergo core-collapse when they are cool M-type supergiants. However the only two detections of a SN progenitor before
explosion are SN1987A and SN1993J, and neither of these was an M-type supergiant. Attempting to identify the progenitors of
supernovae is a difficult task, as precisely predicting the time of explosion of a massive star is impossible for obvious
reasons. There are several different types of supernovae which have different spectral and photometric evolution, and how
exactly these are related to the evolutionary states of the progenitor stars is not currently known. I will describe a novel
project which may allow the direct identification of core-collapse supernovae progenitors on pre-explosion images of resolved,
nearby galaxies. This project is now possible with the excellent image archives maintained by several facilities and will
be enhanced by the new initiatives to create Virtual Observatories, the earliest of which (astrovirtel) is already producing results.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
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A. Pastorello S. Valenti L. Zampieri H. Navasardyan S. Taubenberger S. J. Smartt A. A. Arkharov O. Bärnbantner H. Barwig S. Benetti P. Birtwhistle M. T. Botticella E. Cappellaro M. Del Principe F. Di Mille G. Di Rico M. Dolci N. Elias-Rosa N. V. Efimova M. Fiedler A. Harutyunyan P. A. Höflich W. Kloehr V. M. Larionov V. Lorenzi J. R. Maund N. Napoleone M. Ragni M. Richmond C. Ries S. Spiro S. Temporin M. Turatto J. C. Wheeler 《Monthly notices of the Royal Astronomical Society》2009,394(4):2266-2282
We present the results of the one-year long observational campaign of the type II plateau SN 2005cs, which exploded in the nearby spiral galaxy M51 (the Whirlpool galaxy). This extensive data set makes SN 2005cs the best observed low-luminosity, 56 Ni-poor type II plateau event so far and one of the best core-collapse supernovae ever. The optical and near-infrared spectra show narrow P-Cygni lines characteristic of this SN family, which are indicative of a very low expansion velocity (about 1000 km s−1 ) of the ejected material. The optical light curves cover both the plateau phase and the late-time radioactive tail, until about 380 d after core-collapse. Numerous unfiltered observations obtained by amateur astronomers give us the rare opportunity to monitor the fast rise to maximum light, lasting about 2 d. In addition to optical observations, we also present near-infrared light curves that (together with already published ultraviolet observations) allow us to construct for the first time a reliable bolometric light curve for an object of this class. Finally, comparing the observed data with those derived from a semi-analytic model, we infer for SN 2005cs a 56 Ni mass of about 3 × 10−3 M⊙ , a total ejected mass of 8–13 M⊙ and an explosion energy of about 3 × 1050 erg . 相似文献