... 2011 May 23 . An Unexpected Flare from the Crab Nebula . ... As recently as one month ago, gamma-ray observations of the Crab Nebula by the Fermi Gamma Ray Space Telescope showed an unexpected increase in gamma-ray brightness, becoming about five times the nebula's usual gamma-ray brightness, and fading again in only a few days. ... The above image shows how the Crab Nebula normally appears in gamma rays, as compared to the Geminga pulsar, and how it then appeared during the recent brightening. ...

An Unexpected Flare from the Crab Nebula . ... Credit Copyright: NASA , DOE , Fermi LAT , R. Buehler ( SLAC , KIPAC ) Explanation: Why does the Crab Nebula flare? ... As recently as one month ago, gamma-ray observations of the Crab Nebula by the Fermi Gamma Ray Space Telescope showed an unexpected increase in gamma-ray brightness, becoming about five times the nebula's usual gamma-ray brightness, and fading again in only a few days. ... NASA Web Site Statements, Warnings, and Disclaimers . ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Armagh Observatory, 30 July 2015: The sky above a nearby "failed star" or brown dwarf lying in the summer constellation Lyra shimmers with a beautiful green and yellow aurora ten thousand times brighter than the northern lights. ... Even a few years ago, brown dwarfs were thought by most astronomers to be incapable of emitting any significant radio emission, so its first detection came as a great surprise. ...

... ATNF Home . About ATNF . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . Mopra radio telescope . ... Australia Telescope Online Archive (ATOA) . ... Parkes | ... Australia Telescope 20GHz Survey . ... Visiting Parkes radio telescope . ... Parkes radio telescope webcam . ... X-Ray Microlensing of Bright Quasars . ...

... A star party is a gathering of amateur astronomers who set up their telescopes and observe the dynamic night sky. ... Star parties are best scheduled during first quarter and waxing gibbous Moon. During full moon, the moon is so bright it obscures a view of other celestial objects and even the Moon is best viewed when NOT full. ... We will consult local weather forecasters and make a decision by 2:00p on the day of the star party. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

Proposal Identification No.: ... For these observations night-time is not needed. Begin ­ End Interval ­ Interval 1700 ­ 2200 ­ ­ ­ Days Needed at This Interval 14 Time Constraints (Must Be Justified in the Prop osal Text) In order of scheduling: 2 gridding sessions : 3.5h and 2.5h (ALFA) Starting at least a week later (L-wide or 327MHz, TBD by the gridding sessions ): 3 sessions of 3h each on successive days 1 session of 3h a week later 1 session of 3h two weeks later 11 monthly ...

... The Galactic low-mass X-ray binary GS 2023+338 was discovered during the burst on May 22, 1989 with the Japanise satellite Ginga (aka Galaxy). The flux reached 17 crabs (this unit of flux measurement is an bright X-ray source, Crab Nebula) at 10-35 keV. ... No other radio telescope worldwide carried out multi-frequency measurements. ... Upon 14 days the radio flux fell below the detection level at the RATAN-600 in relation to the decrease of the X-ray flux. ...

Next: Analysis in the Up: MIDAS utilities for Previous: Fourier analysis . For the detection of smooth signals, e.g. sinusoids, use either SCARGLE/TSA or AOV/TSA with bins. ... SCARGLE/TSA -- . Scargle sine model: This command computes Scargle's (1982) periodogram for unevenly spaced observations x . ... In this way, the command can be used to perform a CLEAN-like analysis manually by removing individual oscillations one by one in the time domain (see Roberts et al. ... AOV/TSA -- . ...

... Bringing news from across the Universe to children all around the world . ... Gamma-Ray Bursts are the brightest explosions in the Universe. ... We only see Gamma-Ray Bursts in very distant galaxies; galaxies so far away that it takes billions of years for their light to reach us. ... Astronomers think that Gamma-Ray Bursts are caused by the detonation of massive stars at the end of their lives. These blazing bursts of light are normally followed by a fainter afterglow. ...

Next: *timsort* Up: Timing Analysis Previous: Summary of tasks in . ... Events will be time ordered in the output file. xt> timsort xdata$snr psr ``c 503 513 24'' none A light curve is then generated and plotted so we can inspect the gross properties of the sample (the sequence of good-data intervals and gaps) and any source variability. xt> ltcurv psr none psr 500 xt> ltcplot psr_ltc Finding this sample satisfactory, we search for periodicity with a fast Fourier transform. ...

An Ancient Universe: How Astronomers Know the Vast Scale of Cosmic Time . THE ANCIENT UNIVERSE . c) The Age of Light from the Most Distant Galaxies: The "Time Machine" Effect . ... Thus we are actually seeing these galaxies not as they are today, but as they were billions of years ago. ... The Universe: An Overview | ... The Ancient Universe - The Age of the Expanding Universe - The Age of the Oldest Stars - The Age of Light From Distant Galaxies - The Age of the Chemical Elements | ...