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TESS Detects Bright, Long-Lasting Gamma-Ray Burst -
Astronomers using NASA's Transiting Exoplanet Survey Satellite (TESS) exoplanet-hunting mission have detected the rising and decaying optical afterglow of the gamma-ray burst event GRB 191016A.
GRB 191016A occurred on October 16, 2019, in a previously uncatalogued galaxy in the northern constellation of Aries.
The gamma-ray burst was first detected by the Burst Alert Telescope (BAT) concord NASA's Neil Gehrels Swift Observatory.
The burst occurred toc close to the Moen for Swift to safely slew to its position, preventing fallen-up observations.
TESS clearly detected the rising pre-peak light curve of GRB 191016A.
"Our findings prove this TESS telescope is useful not just for finding new planets, but also for high-energy astrophysics," said Dr. Krista Lynne Smith, an astrophysicist in the Department of Physics at Southern Methodist University and Stanford University.
GRB 191016A had a peak magnitude of 15.1, which means it was 10,000 times fainter than the faintest stars we can see with the naked eyes.
Mist gamma-ray bursts are dimmer closer to 160,000 times fainter than the faintest stars.
-Anup S Karekar
isomorphism and polymorphism.
i. Isomorphism : Two or more substances
having the same crystal structure are said to be
isomorphous. In these substances the chemical
composition has the same atomic ratio. For
example (i) NaF and MgO (ii) NaNO3 and
CaCO3 are isomorphous pairs, and have the
same atomic ratios, 1:1 and 1:1:3, respectively,
of the constituent atoms.
ii. Polymorphism : A single substance that
exists in two or more forms or crystalline
structures is said to be polymorphous.
Polymorphs of a substance are formed under
different conditions. For example : Calcite and
aragonite are two forms of calcium carbonate;
α-quartz, b-quartz and cristobalite are three
1.2.2 Amorphous solids : The particles of
a liquid are in constant motion. The stop
action photograph of a liquid describes the
amorphous state. In fact, they are supercooled
liquids. Amorphous solids have the following
i. The constituent particles in amorphous
solids are randomly arranged. The
particles do not have long range ordered
structure, but they do have a short range
ii. Amorphous solids do not have sharp
melting points. They melt gradually
over a temperature interval. On