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Astronomy in the news
Five separate observations, with nothing in common but the sky. A total eclipse over northern Spain gave the corona a rare clear view from the ground; a companion star may explain why Betelgeuse dims; a ten sided wave was found around Saturn's south pole; an American telescope was launched to weigh dark energy and map dark matter; and India's only dark sky reserve, at Hanle, held its fourth star party.
UPSC has asked
- Prelims 2025: solar flares and coronal mass ejections striking the outer atmosphere
- Prelims 2023: Cepheids, nebulae and pulsars
Why the corona needs a total eclipse
- A solar eclipse happens only at new moon, when the Moon passes between the Earth and the Sun.
- The inner corona is too faint to see against the glare of the solar disc.
- A coronagraph blocks that disc artificially, but scattered light often spoils the view.
- Only in totality, seen from the narrow path of totality, does the Moon block the whole disc, which is the best way to see the inner corona from the ground.
- The corona's magnetic field drives solar flares and coronal mass ejections, which disturb satellites, navigation and communications on Earth.
Betelgeuse and Saturn, before these observations
- Betelgeuse is a red supergiant in the constellation Orion.
- Its brightness rises and falls on a six year cycle, for which there was no agreed explanation.
- Saturn's north pole carries a long lasting six sided wave, known as the hexagon.
India's only dark sky reserve
- Ladakh's administration notified the Hanle Dark Sky Reserve (HDSR) in December 2022, India's first.
- It lies inside the Changthang Cold Desert Wildlife Sanctuary.
- The Indian Institute of Astrophysics (IIA), under the Department of Science and Technology (DST), runs the observatory there.
- No Indian law creates the designation, so the notification is the Union Territory's own.
- Abroad the status is certified by DarkSky International, once the International Dark-Sky Association.
What the Roman telescope carries
Wide Field Instrument
- An infrared camera
- Maps galaxies through gravitational lensing, the bending of light by the gravity of unseen mass in between
Coronagraph
- Blocks starlight to reveal planets around stars
What the universe is made of
- About 5% Ordinary matter. Stars, planets, gas, us
- About 27% Dark matter. Unseen mass holding galaxies together
- About 68% Dark energy. Speeding up the expansion
What has happened
15 Sep 2026
Hanle held its fourth star party, drawing astronomy enthusiasts from across India.
6 Sep 2026
Scientists reported a ten sided wave, a decagon, around Saturn's south pole, the first found there.
- It drifts slowly eastward.
- It may be formed by unstable winds or by a nearby anticyclone.
2 Sep 2026
The National Aeronautics and Space Administration (NASA) launched the Nancy Grace Roman Space Telescope on 30 August, to survey dark energy, dark matter and exoplanets.
- It works from Lagrange Point 2, as the James Webb Space Telescope does, while Hubble orbits the Earth.
30 Aug 2026
Astronomers using the Very Large Telescope found strong evidence of a close companion to Betelgeuse, named Betelgeuse B.
- It appears to be a young star of about 2.6 to 3.1 times the Sun's mass.
- It could explain the six year cycle, because it periodically blocks part of the star's light.
- A second observation is awaited to confirm the finding.
The Hindu, 30 Aug 2026: Betelgeuse may have a companion star (opens in a new tab)
12 Aug 2026
A total solar eclipse crossed Greenland, western Iceland, northern Spain, north eastern Portugal and northern Russia, Europe's first in 27 years.
- It was not seen from India.
The Hindu, 13 Aug 2026: Total solar eclipse over northern Spain (opens in a new tab)