... 2006 December 19 . Massive Stars in Open Cluster Pismis 24 . Credit: NASA , ESA and J. M. ApellАniz ( IAA , Spain). Explanation: How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, making it a record holder. ... Component stars would still remain near 100 solar masses, making them among the more massive stars currently on record. ... About APOD | ...

Supernova 2009js in NGC 918 . This page is devoted to information on Supernova 2009js in NGC 918 . Basic information on this SN, including the last reported brightness, on this Supernova can be found on the main page . Information on the original web pages for many of these images can be found on the updates and links web pages. Discovered independently by Lick Observatory Supernova Search (USA) and Koichi Itagaki (Japan). ... 2009/10/11.44 . 17.2 . ... Joseph Brimacombe . ...

... Star Forming Region NGC 6357 . ... For reasons unknown, NGC 6357 is forming some of the most massive stars ever discovered. Near the more obvious Cat's Paw nebula, NGC 6357 houses the open star cluster Pismis 24, home to these tremendously bright and blue stars. Massive Stars in Open Cluster Pismis 24 . ... Last Thursday evening, stars were not the only lights in Iowa skies. ... Large spiral galaxy NGC 1055 (top left) joins spiral M77 in this lovely cosmic view toward the constellation Cetus. ...

... 2000, ApJ, 537, L49 . ... F. Palla . Invited Talk at the IAU Symposium 200 "The formation of binary stars" eds. R.D. Mathieu and H. Zinnecker (ASP Conf. Ser.) in press . Optical follow-up of ROSAT discovered candidate members of the open cluster Coma Berenices . ... 2000, A , in press . ... 2000, ApJ, in press . ... 2000, ApJ, in press (Sept. ... 2000, ApJ Lett., in press . ... Click to examine publications from other years . ... Star Formation Group . ... Arcetri Home Page . ...

... Updates to HST Standard-Star Fluxes . ... These data are in an STScI data base named CRCALSPEC and have been divided into two categories to help the user understand the origin and accuracy of these flux distributions. ... 1990, ApJS, 73, 413) and Oke (1990, AJ, 99, 1621) spectra are available. Oke (1990) used the DoubleSpectrograph on the 5-m Hale Telescope to obtain these spectra for HST calibration; and these data are identified in the HST data bases by the keyword OBSMODE=OKE DBSP. ...

... Stellar Evolution is driven entirely by the never ending battle between Pressure and Gravity . As imbalances are reached, the star is driven to find a new Energy source. ... Pressure and gravitational forces are equal, the star is stable and its core is sufficiently hot to fuse Hydrogen into Helium More about main sequence stars . ... The luminosity generated by the core fusion of Helium into Carbon is far greater than the shell luminosity associated with the fusion of Hydrogen into Helium. ...

... Updated 2008 December 22nd . ... Updated 2008 December 18th . ... Updated 2008 December 17th . ... Updated 2008 December 16th . ... Updated 2008 December 15th . ... Updated 2008 December 10th . ... Updated 2008 December 2nd . ... Some Videos on our Web Sites . ... Cool October . ... Updated 2008 October 31st . ... Updated 2008 October 15th . ... Updated 2008 October 10th . ... Updated 2008 October 9th . ... Updated 2008 October 8th . ... Updated 2008 October 7th . ... Updated 2008 October 2nd . ...

... To be read in conjunction with Section 4.11 of the WFPC2 Instrument Handbook , -Version 4.0. ... 1 The second study found evidence that CTE loss for faint stars has increased with time (Whitmore, 1998). The primary observational consequence of CTE loss is that a point source at the top of the chip appears to be fainter than if observed at the bottom of the chip, due to the loss of electrons as the star is read out down the chip (see Figure 1 ). ... Last updated: 06/16/98 10:38:00 . ...

... new: . ... Python 2.6.2 + most up-to-date modules (December 2009) . ... pyQC script structure . ... The current installation of python and its associated modules on our DFO machines is extremely old (i.e. python 2.4.2 was released in Sept. ... The new python executable lives in: /qcdp/bin/python . ... The first figure shows the execution times for the old python installation, while the second figure shows the execution times based on scripts running the python 2.6.2 installation with the new modules...

Chandra X-Ray Observatory CXC 1. ... E0102: Joint Fits with ACIS S3, MOS1/2 & pn Paul Plucinsky, Joseph DePasquale, & Steve Snowden Paul Plucinsky 1 EPIC Cal April 2007 Chandra X-Ray Observatory 1. ... E0102: Gratuitous Pretty Pictures of E0102 S3 Summed Data ~100 ks CXC RGS Spectrum (Pollock 2006) Objective: develop a spectral model which can be used by RGS, HETG, EPIC & ACIS, etc. ...

. This is the CIMA standard on/off menu: . The following is the on-line help page for standard on/off: . You can return to the main CIMA page by clicking here .

The "ring of fire" seen by satellite cameras around the polar caps (picture below) is probably created by electrons leaking from the tail's plasma sheet, whose magnetic field lines form a somewhat imperfect trap. ... One possible explanation involves the close association between auroral arcs and electric currents which flow along field lines between the ionosphere and distant space ( Birkeland currents ). ... That produces an extra resistance to the flow of current. ...

... The study of the Large-scale structure of the Universe and measurements of the Dark Energy equation of state; The exploration of the growth and cosmological evolution of supermassive Black holes in the Universe. ... In course of the all sky survey SRG will discover about 100 000 galaxy clusters and 3 million AGNs. Galaxy clusters are the largest gravitationally bounded objects in the Universe and are best explored through the study of X-ray emission from the hot intergalactic gas. ... 2016 IKI RAN ...

... VLBI Schedule . LBA Home Page . ... LBA Correlation . ... Observers Wiki . ... Main / . ... Meeting ID: 0530 . ... UTas : Jim (Chair), John D. Curtin: Aiden, Hayley, Cormac, Claire, Aquib . ATNF: Tasso, Chris . ... e-VLBI demo to Curtin (Tzioumis/Tingay) . ... Options for disks and data transport: . Buying excess disks from Swinburne VLBI pool and/or Mk5 disks. ... Initiate discussion on next generation VLBI systems and disks (Mk5b/Mk5c/of-the-self) for the March LBA meeting. ...

... Ultraluminous X-ray sources (ULXs) are located in external galaxies, their X-ray luminosities (10 39 - 10 41 erg/s) are thousand times greater than those of brightest black holes in the Galaxy. ULXs may be supercritical accretion disks around black holes of stellar masses (~10 Solar masses) like that in SS433, or they may be a hypothetical intermediate-mass black holes (hundreds - thousands Solar masses) with standard accretion disks. ... 2) The ULX progenitors were ejected from the star clusters. ...

... The material in "From Stargazers to Starships" meets several important requirements of the national standards. Pages cited below are from National Science Education Standards National Academy Press, Washington 1995. ... For example: the sections on astronomy not only describe calendars and sundials (including their construction), but also the astronomy of the ancient Greeks, including two different ways in which ancient Greeks estimated the distance to the Moon. ...

... Next: FITS Checksum Verification Up: Data Models and Previous: A Proposed Convention . ... The FITSIO Subroutine Library has been available for 3 years, and has matured into a stable, full-featured interface for reading and writing FITS format files. ... The FITSIO subroutine library for reading and writing FITS files is now three years old and is used by many projects as the standard programming interface for accessing FITS format data files. ...

... see also previos version 1991 VII/158 A REVISED AND UPDATED CATALOG OF QUASI-STELLAR OBJECTS ================================================================================ HEWITT A., BURBIDGE G.: 1993 Astrophys. ... A standardization of the files and their description was performed at CDS to allow automatic conversions to FITS tables. The paper contains a catalog of all known quasi-stellar objects (QSOs) with measured emission redshifts, and BL Lac objects, complete to 1992 December 31. ...

In autumn 1994, two groups of astronomers announced that they had discovered Cepheid variable stars in a distant cluster of galaxies. ... As the term suggests, variable stars change in brightness over time. ... Variable stars are an ideal way to get high-school students doing real science, with real data, from the real sky. ... a sky chart to find the stars . ... Students can use the nearby stars to estimate the magnitude of Delta. ... Locate the star Delta in Cepheus and estimate its brightness . ...

Describes how funtools can be integrated into the ds9 Analysis menu. SAOImage/DS9 is an astronomical imaging and data visualization application used by astronomers around the world. DS9 can display standard astronomical FITS images and binary tables, but also has support for displaying raw array files, shared memory files, and data files automatically retrieved via FTP and HTTP. ... It can be manually loaded into DS9 from the Load Analysis Commands ... option of the Analysis menu. ...