tag:blogger.com,1999:blog-1028287563520537999.post335129824597716963..comments2023-12-27T05:22:24.378-05:00Comments on Simostronomy: New Type of Variable Stars Discovered With Just a DASCH of EvidenceBig Mikehttp://www.blogger.com/profile/08315391586724045202noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-1028287563520537999.post-11211953691214440902010-03-30T23:48:50.710-04:002010-03-30T23:48:50.710-04:00It appears that anonymous above is slightly confus...It appears that anonymous above is slightly confused: though the first star shows all the spectroscopic signs of being an RS CVN binary, no radial velocity variability has been detected for it. The authors of the discovery paper instead mention that J0736 might be an RS CVN binary, which is also plausible, even though it's NOT as chromospherically active as J0830. Even if both stars ARE RS CVN stars, this is still excellent work as it shows decadal variations which are much larger than have been observed on all but a small handful of RS CVN stars (and that data is, naturally, also from the Harvard archives).Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1028287563520537999.post-37426979818714859282010-03-11T13:55:23.480-05:002010-03-11T13:55:23.480-05:00I added the word class in to make it clearer. Than...I added the word class in to make it clearer. Thanks for the suggestion.Big Mikehttps://www.blogger.com/profile/08315391586724045202noreply@blogger.comtag:blogger.com,1999:blog-1028287563520537999.post-87056528248378686992010-03-10T21:57:13.043-05:002010-03-10T21:57:13.043-05:00Great article. Fascinating.
One minor nit to pic...Great article. Fascinating.<br /> <br />One minor nit to pick - I think you are missing a word with "luminosity of III" - class /type after luminosity maybe?<br /><br />A whole new class of variable perhaps. That's cool. I wonder if these have any relation to "secular" or historical variable stars also thought to have possibly faded over millennia such as Denebola (Beta Leonis), Zubeneschamali (Beta Librae) and Alchiba (Alpha Corvi) - except those are very much the wrong spectral type - A rather than K.StevoRhttps://www.blogger.com/profile/02506855815096149912noreply@blogger.comtag:blogger.com,1999:blog-1028287563520537999.post-90749250132235576332010-02-28T19:45:45.801-05:002010-02-28T19:45:45.801-05:00Great article Mike. Data mining rocks!!!
PeterGreat article Mike. Data mining rocks!!!<br /><br />PeterAstroswannyhttps://www.blogger.com/profile/03935485524427754485noreply@blogger.comtag:blogger.com,1999:blog-1028287563520537999.post-21220071144281747102010-02-28T13:19:07.572-05:002010-02-28T13:19:07.572-05:00The first of the three stars is pretty evidently a...The first of the three stars is pretty evidently an RS CVn star, from the ASAS3 and NSVS data, with secular trends in mean magnitude and amplitude. The DASCH long term trend doesn't conflict with secular trend. This would tally with the radial velocity evidence for binarity. Not to mention the source paper's mention of detection of chromospheric activity. In fact, I now see that they even mention the RS CVn candidacy in the source paper<br /><br />http://arxiv.org/abs/1001.1395<br /><br />based on astrophysical criteria, and the ASAS3 data certainly confirm it. Nothing new in terms of variability type there then.<br /><br />The other two objects show things not unprecedented amongst post AGB yellow and orange semiregular (super)giants. post AGB variables with fading events are very mixed as to particulars of fade(s), although with general similarities, and often not even listed in the GCVS, or lost amongst all the other semiregulars if included. There aren't classic type star class names for these objects.<br /><br />Not all such giants are known to vary, and not all of them are in need of Helium or Lithium shell flashes to explain things.<br /><br />The classic well known K2 III supposed Thick Disc Giant Star is called Arcturus.<br /><br />Not that discovering new examples of these objects is not important, but there is nothing particular new about them.Anonymousnoreply@blogger.com