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Variable Stars Observer Bulletin 15.000 – 30.000 the appropriate amount of shots with the same comparison stars and their brightness in the range exposures. Making the Flat files is a little more the data frames are. Amateurs' Guide to Variable Stars September-October 2013 | Issue #2 complicated. Ideally, they are easy to get on evening or predawn twilight sky. You need to With a series of photometric observations, we can choose the exposure to get a ¼ - ½ of the value of build a light curve, find the period of a variable complete saturation of the pixel. For example, full star, other parameters, depending on the saturation for 16 bit camera is 65535. The value of variability type. a pixel in the Flat file should be in the range of Variable Stars Observer Bulletin 15.000 – 30.000. I use 20.000. There are lots of software to make the analysis of the photometric data. A good example is a ISSN 2309-5539 Another way of obtaining the Flat files is to use the software package created by Andrey Prokopovich so-called flat-box. I use a white screen which is and Ivan Adamin (the VS-COMPAS project core attached to the dome. Am bringing him a team). There are desktop and web versions Twenty new W Ursae Majoris-type eclipsing telescope and the illuminating light bulb. For more available. It is a powerful software that allows you binaries from the Catalina Sky Survey scattered light, the telescope tube can be covered to build the light curves, search for possible with a white cloth. Flat files must be taken periods, combine data from a number of separately for each filter. The number of photometric surveys and more. calibration frames depends on a particular camera model. I usually make 15-20 frames of each type. I would also like to mention another program called MCV created by professor Andronov. The Once the calibration files are completed, the program is unique in its kind and allows you to observational data can be processed. The first make a very accurate and detailed analysis of the Details for 20 new step is to calibrate frames containing the target photometric data. WUMa systems are object using the same calibration files. At this step presented, along we get a clear picture without any unnecessary with a preliminary noise content. The second step is photometry Valery Tsehmeystrenko The FU Orionis phenomenon model of the FU Orionis stars are pre-main-sequence measurements. Don't forget to specify multiple totally eclipsing eruptive variables which appear to be a system GSC stage in the development of T Tauri 03090-00153. stars. Image: FU Orionis. Credit: ESO The FU Orionis phenomenon: further reading (references) – see p.3 for the article NSVS 5860878 = Dauban V 171 Carbon in the sky: • Herbig, G. H., Eruptive phenomena in early stellar evolution, 1977, ApJ, 217, 693 A new Mira variable in Cygnus a few remarkable carbon stars • Herbig, G.H.; Bell, K.Robbin, Third Catalog of Emission-Line Stars of the Orion Population, 1988; The list of the most Lick Observatory Bulletin, 1111, 90 interesting and • Vittone, A.A., Errico, L., FU Orionis systems, 2005, Mem. S.A.It. Vol. 76, 320 bright carbon stars • Hartmann, L. & Kenyon, S. J., 1985; On the nature of FU Orionis objects, ApJ, 299, 462 for northern observers is presented. • Hartmann, Lee; Kenyon, Scott J., 1996; Ann. Rev.of Astr. and Astroph., 34, 207 • Percy, J. R., 2007, "Understanding variable stars", Cambridge University Press, pp. 289-290 • Discovery of possible FU-Ori and UX-Ori type objects; online: http://crts.caltech.edu/CSS091110.html • FU Orionis Stars; online: http://www.astro.umd.edu/~neal/fuori.html Right: TT Cygni. A carbon star. • FU Orionis; online: http://www.nightskyinfo.com/archive/fu_orionis/ Credit & Copyright: • The Herbig-Bell Catalog; online: http://www.stsci.edu/~welty/HBC/HBC.html H.Olofsson (Stockholm Observatory) et al. • The Furor over FUORs; online: http://www.universetoday.com/78796/the-furor-over-fuors/ Nova Delphini 2013 Nova has reached The VS-COMPAS Project magnitude 4.3 visual The "Heavenly Owl" on August 16 observatory: The project was started in fall of 2011 by four amateur astronomers from Belarus. The main intention is to expand the International Variable Star Index (VSX) catalog with new variable stars, variable stars data analysis and seeing above research. Among the most significant achievements it is worth to mention more than 1200 variable stars discovered the Black Sea by combined efforts of seven active team members. All data about discovered stars is submitted to the VSX catalog running by the AAVSO. Another valuable goal the project has is increasing public interest to variable stars science. waterfront More information about the team and discoveries can be found at http://vs-compas.belastro.net VS-COMPAS Project: variable stars research and data mining. More at http://vs-compas.belastro.net 24 Variable Stars Observer Bulletin (Amateurs' Guide) | September-October 2013 Software is the key The software allows you to specify any sequence, Variable Stars Observer Bulletin the automatic change of filters, exposure time, Amateurs' Guide to Variable Stars One more, and the last, thing that is needed to number of frames and more. The number of start the observations and study of variable stars images and the intervals between them depend on is software. There are too much of software the observed object, or rather of his period. The September-October 2013 | Issue #2 available to be able to discuss it all. Let's focus more frames you make, the more light C O N T E N T S only on those samples which are widely used by measurements you can get for the object - the the amateurs of astronomy for variable stars more accurate the resulting light curve will be. observations. 04 NSVS 5860878 = Dauban V 171: a new Mira variable For a short-period variable star the frames should in Cygnus For autoguiding the ProGuider, Guidemaster, PHD be taken continuously or with minimal pauses. It is by Ivan Adamin, Siarhey Hadon Guiding, GuideDog or Maxim DL can be used. The better to cover the whole period with one session, A new Mira variable in the constellation of Cygnus is presented. The variability of the NSVS 5860878 source was detected in January of 2012. latter is a true all-in-one processor, which does all if the period is comparable to the duration of the Lately, the object was identified as the Dauban V171. A revision is the above programs do, and much more. For night time and object visibility. For example, for submitted to the VSX. photometry measurements the IzmCCD, Maxim intermediate polars, the observations of which, in DL are primarily used. Don't forget about preparing particular, are held at the "Heavenly Owl" a 06 Twenty new W Ursae Majoris-type eclipsing binaries the maps when you plan observations. This is continuous shooting is required at the minimum Credit: Justin Ng from the Catalina Sky Survey essential if you are going to observe a set of shutter speed. This is due to the presence of two by Stefan Hümmerich, Klaus Bernhard, Gregor Srdoc targets during the night. You need a good time periods, one of which can be from tens of seconds 16 Nova Delphini 2013: management skills to cover many targets in a to 20 minutes. a naked-eye visible flare in A short overview of eclipsing binary short period of time. northern skies stars and their traditional As an example, I present (see the light curve by Andrey Prokopovich classification scheme is given, which concentrates on W Ursae Majoris On the AAVSO website there is a good chart below) the light curve of an interesting binary plotter http://www.aavso.org/vsp . It can generate system in the constellation of Lyra. This is the On August 14, 2013 a new bright star (WUMa)-type systems. (6.3m) was detected in the constellation Details for 20 new WUMa systems star maps with the desired coordinates and field of result of observations made at the observatory of Delphinus on the frames taken by are presented, along with a view. Also, there you can get a table with the "Heavenly Owl" during the summer of 2013. Koichi Itagaki (Yamagata, Japan). Later it preliminary model of the totally parameters of the comparison stars, which are Measurements are done in visual band. was assigned a status of Nova Delphini eclipsing system GSC 03090-00153. 2013 and became the brightest nova surrounded by the observed variable star. since 2007, visible to a naked eye at its In the case of the long-period variable stars, there maximum brightness. 10 MISCellaneous variables revision: new elements and Now we have prepared all the necessary is no need for a large number of frames. Take classification for 10 MISC records in the VSX equipment and got it snapped to the sky by known several shots in each filter. At the end of the 03 The FU Orionis by Siarhey Hadon, Ivan Adamin bright stars, focused and ready for observations. observations set, we still have to make the phenomenon Take a test single shot. The duration of exposure calibration frames. They can be of three types: by Ivan Adamin Updated periods and variability class for ten MISC records from the VSX database are presented. Own software is used for candidates selection, depends on the characteristics of your FU Orionis stars are pre-main-sequence found a set of records for which periods can be improved considerably. camera and magnitude of stars that you eruptive variables which appear to be a want to measure. Start with 15-20 seconds.
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