תוכן
תמונות
הוסף תמונה שלך
DSS Images Other Images
מאמרים קשורים
Early Infrared Spectral Development of V1187 Scorpii (Nova Scorpii 2004 No. 2)
We report on an unprecedented infrared time series of spectra of V1187Sco, a very fast ONeMg nova. The observations covered a 56 day period(2004 August 6-September 30) starting 2 days after the nova's peakbrightness. Time evolution of the spectra revealed changing linestrengths and profiles on timescales of less than a day to weeks as thenova evolved from early postmaximum to early coronal phases. When ourground-based optical and Spitzer Space Telescope data were combined, thewavelength coverage of 0.38-36 μm allowed an accurate spectral energydistribution to be derived when it was about 6 weeks after outburst.Developing double structure in the He I lines showed them changing fromnarrow to broad in only a few days. Using the O I lines in combinationwith the optical spectra, we derived a reddening of E(B-V)=1.56+/-0.08and a distance of 4.9+/-0.5 kpc. Modeling of the ejected materialstrongly suggested that it was geometrically thick withΔR/R=0.8-0.9 (more of a wind than a shell) and a low fillingfactor of order a few percent. The line shapes were consistent with acylindrical jet, bipolar, or spherical Hubble flow expansion with amaximum speed of about -3000 km s-1. The central peakappeared to be more associated with the spherical component, while thetwo peaks (especially in Hβ) suggested a ring with either a lowervelocity component or with its axis inclined to the line of sight.
| Far-Ultraviolet Stellar Photometry: Fields Centered on rho Ophiuchi and the Galactic Center
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996ApJS..104..101S&db_key=AST
| Far-ultraviolet stellar photometry: Fields in Sagittarius and Scorpius
Far-ultraviolet photometry for 741 objects in a field in Sagittariuscentered near M8 and 541 objects in a field centered near sigma Scorpiiis presented. These data were extracted from electographic imagesobtained with two cameras during a shuttle flight in 1991 April/May. Thecameras provided band passes with lambdaeff = 1375 A andlambdaeff = 1781 A. Synthetic colors show that these bandsare sensitive to effective temperature for hot stars. Our measurementswere placed on a quantitative far-ultraviolet magnitude scale byconvolving the spectra of stars observed by IUE with our cameras'spectral response functions. Fifty-eight percent of the ultravioletobjects were identified with visible stars using the SIMBAD databasewhile another 40% of the objects are blends of early type stars tooclose together to separate with our resolution. Our photometry iscompared with that from the TD-1, OAO 2, and ANS satellites and the S201(Apollo 16) far-ultraviolet camera and found to agree at the level of afew tenths of a magnitude. Unlike previous studies, almost half of theidentified visual counterparts to the ultraviolet objects are early Bstars. A plot of distance modulus against ultraviolet color excessreveals a significant population of stars with strong ultravioletexcess.
|
הכנס מאמר חדש
לינקים קשורים
הכנס לינק חדש
משמש של הקבוצה הבאה
|
תצפית ומידע אסטרומטרי
| קבוצת-כוכבים: | קשת |
| התרוממות ימנית: | 17h48m25.56s |
| סירוב: | -16°49'37.9" |
| גודל גלוי: | 8.368 |
| מרחק: | 297.619 פארסק |
| תנועה נכונה: | -3.2 |
| תנועה נכונה: | -11.5 |
| B-T magnitude: | 8.573 |
| V-T magnitude: | 8.385 |
קטלוגים וכינוים:
|
