VHE Gamma-Ray Emission from H1722+119

H1722+119 is a BL Lac object, that was listed as candidate TeV blazar in Costamante & Ghisellini (2002) based on its X-ray and radio properties. Its redshift is uncertain; Sbarufatti et al. 2006 give z>0.17. The source has been detected by Fermi-LAT, in the Second Fermi Catalogue with F(>1 GeV) (3.7+-0.3)e-09 cm^-2 s^-1 and with spectral index 1.92+-0.06.

H1722+119 was observed for five nights by the MAGIC telescopes starting May 17th 2013 and collecting 11 hours of good quality data. A preliminary analysis yields a detection of the source with a statistical significance of more than 5 standard deviations. The VHE flux of this detection is about 2% of the flux from the Crab nebula above 140 GeV. The previous VHE gamma-ray observations of the source produced an upper limit of 4.2% Crab nebula flux above 140 GeV (Aleksic et al. 2011).

The MAGIC observations were triggered by the extended optical high state of the source, reported by the Tuorla blazar monitoring program (http://users.utu.fi/kani/1m). At the beginning of May 2013 the source reached an R-band magnitude of 14.65, the brightest ever observed since 2005, when the monitoring started. We also analyzed the Fermi-LAT data, finding indication of a spectral index harder than reported in the Second Fermi Catalog. A Swift-XRT ToO observation was performed on 20th May.

MAGIC will continue the observations of the source as soon as the moon conditions allow it again and multiwavelength observations are encouraged.

The MAGIC contact persons for these observations are J. Cortina (cortina@ifae.es) and E. Lindfors (elilin@utu.fi).

MAGIC is a system of two 17m-diameter Imaging Atmospheric Cherenkov Telescopes located at the Canary island of La Palma, Spain, and designed to perform gamma-ray astronomy in the energy range from 50 GeV to greater than 20 TeV. 

http://www.astronomerstelegram.org/?read=5080

Shockingly bright burst

A record-setting blast of gamma rays from a dying star in a distant galaxy has wowed astronomers around the world. The eruption, which is classified as a gamma-ray burst, or GRB, and designated GRB 130427A, produced the highest-energy light ever detected from such an event.

"We have waited a long time for a gamma-ray burst this shockingly, eye-wateringly bright," said Julie McEnery, project scientist for the Fermi Gamma-ray Space Telescope at NASA's Goddard Space Flight Center in Greenbelt, Md. "The GRB lasted so long that a record number of telescopes on the ground were able to catch it while space-based observations were still ongoing."

Just after 3:47 a.m. EDT on Saturday, April 27, Fermi's Gamma-ray Burst Monitor (GBM) triggered on eruption of high-energy light in the constellation Leo. The burst occurred as NASA's Swift satellite was slewing between targets, which delayed its Burst Alert Telescope's detection by a few seconds.....

You can see more details in this link: 

NASA's Fermi, Swift see 'shockingly bright' burst