Statistics of sunspot activity . The sunspot indices . ... NGDC's observations . The solar regions . ... The average annual indices of sunspot activity . Visual indices of solar activity by National Geophysical Data Center . ... 0.06 . ...

... X-Ray Binaries I . ... In late January 2000 Cygnus X-3 made a transition from a quiescent radio state (low X-ray state) to a radio flaring state (high X-ray state). ... Throughout this activity an extensive multiwavelength campaign was undertaken. These included observations in the hard X-ray (CGRO/BATSE), X-ray (RXTE/ASM/PCA/HEXTE), radio (GBI, Ryle Telescope, VLA, RATAN-600), radio imaging (VLBA), and high resolution X-ray spectroscopy and imaging (Chandra). ...

WFPC2 . Images: version1 , version2 . Catalogs: Version 1 HDF-S , HDF-N ;Version 2 HDF-S . STIS . ... NICMOS . Images: Camera 3 , V2 of psf-convolved STIS 50CCD on NICMOS . ... Images: WFPC2 FF , STIS FF ; Version2: WFPC2 FF , STIS FF , NICMOS FF . Catalogs: Version2 WFPC2 FF , STIS FF , NICMOS FF . ... Check the instrument specific technical pages for a description of the data products and the implemented data reduction steps: STIS , WFPC2 , NICMOS , Flanking Fields . ...

... ATNF Home . About ATNF . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Australian Square Kilometre Array Pathfinder . Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . Mopra radio telescope . ... Australia Telescope Online Archive (ATOA) . ... Visiting Parkes radio telescope . Visiting Australia Telescope Compact Array . ... Parkes radio telescope webcam . ...

... The earliest X--ray observations were carried out in the mid--1970s. X--ray luminosities of order L erg/sec were detected in the 2-11 keV range in the direction of the Orion star forming region. ... These observations showed that the O and B stars were the brightest X--ray sources, and that TTs were also associated with emission. Feigelson and Kriss (1981) showed that some of the X--ray sources were associated with PMS stars which had not been previously detected which H surveys. ...

NATIONAL ASTRONOMY AND IONOSPHERE CENTER . ... Visitor Center . ... Kick-Off Ceremony of the Arecibo Observatory 50th Anniversary . Observation Night . ... This activity was organized by the staff of the †Бngel Ramos Foundation Visitor Center with the collaboration of the Astronomy Society of Puerto Rico. ... The participants also had the chance to view the exhibits at the †Бngel Ramos Foundation Visitor Center as well as to view the new Arecibo Observatory movie at the AO Amphitheater. ...

... Precisely one month ago, on 11 July 2009, the last active area of the new solar cycle disappeared from the surface of the Sun. Over the 30 days following this, neither observers on Earth nor devices in space have been able to detect the emergence of any sunspots. ... Therefore, it seems that our star has once again returned to a state of deep solar "winter", following several sparks of activity in May-June 2009. ... To date, this period has lasted 30 days. ...

Next: J.E. Chambers, Research Astronomer Up: Research Previous: Research Contents . ... Solar Variability and Climate . Other Activities . ... Applied to data of flares on Gliese866 he was able to estimate the area of hydrogen emitting flare regions as 1-13% of the stellar surface. ... As partners in the project, Armagh Observatory has been asked to contribute to the selection process in exchange for priority access to the data which will eventually flow from the satellite. ...

Extended time series of Solar Activity Indices (ESAI) is database including observational, synthetic and simulated sets to study Solar magnetic field variations and their influence on the Earth. ESAI extend the ordinary lengths of some traditional indices of solar activity: sunspot areas, Wolf numbers (equatorial component of magnetic field of the Sun), polar faculae numbers (polar component), mean latitudes, N-S asymmetry of hemispheres (location of activity). Series . ...

... kupry@sai.msu.ru also kupry@asu.cas.cz . ... Solar expeditions. Astronomical Institute Czech Republic Examples IDL procedures Evpatoria Space Image Evpatoria Winter 2012 European Solar Physics Meeting Digital Images Album IDL Lib Karlovy Vary, 2008 List of publications Masha MAX MILLENNIUM PROGRAM My family (new) HSFA-2, 2005 Ondrejov (brezen 2005 ) Ondrejov webcam Photo Ondrejov observatory Praha SatTV Seznam SOHO Solar eclipse 31 July 1981 Software IDL programmes ...

... The Sun is the closest star to us, and a regular object in our Galaxy. Solar activity manifests itself, primarily, in solar flares - episodic explosive energy release in the form of electromagnetic radiation and high energy particles (electrons and protons). The nature of the flares is related to cyclic variations of global and local magnetic fields in the atmosphere of the Sun. ... Such formations are called active regions. ...