Tag : Blazar

    Observations From 11 Global Telescopes Lead To Detection Of The Brightest Flare Of A Century-Old Blazar

    Telescopes
    Inam Ansari
    May17/ 2023

    New Delhi (The Hawk): The brightness of BL Lacertae (BL Lac), a blazar located about 950 million light years from the Earth and discovered almost a century ago has been found to have reached its maxima. Results published in the latest study, led by post-doctoral fellow Aditi Agarwal from the Raman Research Institute, an autonomous institute funded by the Department of Science and Technology (DST), stated that the flare emanated from BL Lac had reached the maxima on August 21, 2020, which is a novel finding about this source. For several decades now, BL Lacertae (commonly referred as BL Lac), an Active Galactic Nucleus (AGN) source, has remained of significant interest for study among the global astronomy community. Usually located in the core of the galaxy, AGNs are compact structures showing anomalous luminosity from time-to-time. The deviation in their brightness levels can vary and last either for a few hours, days, weeks or even some months. This luminosity variance, when seen with naked human eye, is nothing but the electromagnetic emissions that are visible across the radio, microwave, infrared, optical, ultra-violet, X-ray and gamma wavelengths.   The flaring up and its decay of the emissions from BL Lac was detected using the continuous observations made by an ensemble of eleven optical telescopes located in across the world. One among them was the Himalayan Chandra Telescope located in Ladakh’s Hanle. In early July 2020, astronomers suspected that BL Lac was beginning to flare up. All the eleven telescopes were instantly deployed and focused observations continued for 84 days starting July 13, 2020 till – September 14, 2020. “As time progressed, it was observed that the flare was becoming brighter gradually, indicating t ...

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