... 2006 February 24 . Recurrent Nova RS Ophiuci . ... Explanation: This pretty star field in the constellation Ophiucus is centered on a star not often seen - RS Ophiuci. ... A type of cataclysmic variable star classified as a recurrent nova, RS Oph dramatically increased in brightness from 11th magnitude , too faint to appear on some star charts. ... Such stars are now modeled as interacting binary star systems, composed of a compact white dwarf star co-orbiting with a swollen red giant. ...

... Observing . ... Home Education Workshops at Adorama Astronomy Workshop: Observing Variable Stars from the City ? February 15, 2015 . ... Beyond New York City . ... Observing Resources for Amateur Astronomers - Part 1: Beginning Observers . ... A History of the First Forty Years of the Amateur Astronomers Association . ... Presented by€а Adorama €аFor the Amateur Astronomers Association of New York . ... 2016 Amateur Astronomers Association of New York Designed by Press Customizr Powered by . ...

... Credit Copyright: Hubble Heritage Team , ESA , NASA Explanation: Expanding light echoes continue to illuminate the dusty environs of V838 Monocerotis , mysterious variable star near the edge of our Galaxy. ... While the expanding light echoes are dramatic , astronomers have struggled to understand where V838 Mon itself fits into the stellar life cycle. ... Publications with keywords: v838 mon - variable star - light echo . Publications with words: v838 mon - variable star - light echo . ...

... During the analysis of the surveys carried out on RATAN-600, it was found that almost one fifth of the detected sources shows significant radio flux variations. ... We used the data from "Cold" radio surveys carried out with RATAN-600 in 1980-1994 to search for radio sources with significant flux variability. ... On possibility of detection of variable sources using the data of Cold surveys carried out on RATAN-600. ... Detection of Variable Sources Using the Data of "Cold" Surveys. ...

... February 22, 1999 . NGC 1316: After Galaxies Collide . ... WFPC2 , HST , NASA . ... A preliminary inspection indicates that NGC 1316 is an enormous elliptical galaxy that started devouring a smaller spiral galaxy neighbor about 100 million years ago. ... Most elliptical galaxies have more and brighter globular clusters than evident in NGC 1316 . ... One hypothesis therefore holds that these globulars survive from an even earlier galaxy that was subsumed into NGC 1316. ... About APOD > . ...

. 66%) of the extreme AGB stars are variable and only smaller fractions of carbon-rich (6.1%) and oxygen-rich (2.0%) stars are detected as variable sources. We also detect a population of variable young stellar object candidates. [ ADS ] . ADS Citation Query . # citations = 41 . citations vs. year [year,citations] . [2009,6][2010,6][2011,8][2012,4][2013,4][2014,4][2015,9] . Copyright 2012 Karl D. Gordon All Rights Reserved

... Tonight's Sky . ... Search By Name Enter coordinates Use current location . ... Observing . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... How do astronomers use Cepheid variables to measure distances? ... Get instant access to subscriber content on Astronomy.com! ... If you are already registered on Astronomy.com, please log in below. ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ...

The ESA/ESO Astronomy Exercise Series 2 . The Distance to Messier 100 as Determined by Cepheid Variable Stars . ... The small variations in distance to the individual Cepheid variable stars in the Cloud are negligible compared with the much larger distance to the SMC. ... In this way Cepheid variable stars can be used as one of the 'standard candles' in the Universe that act either as distance indicators themselves or can be used to calibrate (or set the zero point for) other distance indicators. ...

... In order to disentangle the effects of different climate variables on tree-ring growth rates of different species, and to explore the possibility that more than one species could improve the accuracy of the reconstructions of climate using tree rings, a methodical study of trees in close proximity to the Armagh Observatory climate station was initiated together with Ana Maria Garc?a Su?rez, and continued as part of the latter's PhD thesis with John Butler and Professor Mike Baillie (QUB). ...