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When astronomers from the Indian Institute of Astrophysics and their collaborators looked carefully at the galaxy NGC 3785, they found that not only does it have the longest tidal tail discovered so far, but that an ultra-diffuse galaxy is currently being formed at the end of this tidal tail as well. 

This is based on the recently published paper titled "A Tale of NGC 3785: The formation of an ultra-diffuse galaxy at the end of the longest tidal tail", by Watts et al, 2024, Astronomy & Astrophysics, 691, L13.

Press release by PIB published here.

Press release issued by DST here.

Download the paper from here.

The Indian Astronomical Observatory at Hanle, Ladakh celebrated the first day of the year 2025 by witnessing an aurorae yet again. An energetic CME that left the Sun on 29th December 2024 caused an intense geomagnetic storm on 1st January 2025. The aurora that resulted from this storm was captured as a video by the all-sky camera at Hanle. The low frequency radio emission from the CME was also observed and imaged at Gauribidanur Radio Observatory (GRO), and the Active Region behind this storm was imaged at Kodaikanal Solar Observatory. All three observatories are operated by IIA.

The Indian Institute of Astrophysics (IIA) signed a Memorandum of Understanding today with the Rural Development and Panchayat Raj (RDPR) Department of the Government of Karnataka to promote astronomy through the 5880 Arivu Kendras across the state.

Careful modelling of the thermal and ionization structure of a notable Planetary Nebula PN IC 2003, enabled astronomers from IIA to explain the observed multi-wavelength data much better than was possible by earlier researchers. IC 2003 is one of those rare Planetary Nebulae which has a hydrogen-deficient central remnant star of Wolf Rayet type. The astronomers used data from the Vainu Bappu Telescope in Kavalur, Tamil Nadu, which is operated by IIA, as well as data from other space telescopes.

This is based on the recently published paper titled "Photo-ionization structures of Planetary Nebula IC 2003 with [WR] central star", by Khushbu K. and C. Muthumariappan 2024, Advances in Space Research, 74, 3.

Press release by PIB published here.

Press release issued by DST here.

Download the paper from here.

Using Ultraviolet Imaging Telescope (UVIT/AstroSat) data of the Andromeda Galaxy from the public archives, astronomers from the Indian Institute of Astrophysics, Bengaluru have discovered ultraviolet emission from 42 novae, a special class of stellar explosions, and even caught 4 of them in the act of outburst itself. They could then study these interacting binary star systems in our nearest neighbor galaxy at different phases of their life, some piling up matter from their companion, while others spewing it into space.

Press release by PIB published here.

Press release issued by DST here.

Download the paper from here and here.

The paper was highlighted by Nature India as well.

For an extraordinary fourth time during the current solar cycle, intense red coloured auroral activity was seen from Ladakh, India, and was photographed by astronomers of the Indian Institute of Astrophysics (IIA) from Hanle, Leh, and Merak on the night of 10-11 October 2024. The aurora was captured by the all-sky cameras at Hanle and Merak throughout the night. The bright red emission in the northern sky was seen easily with the unaided eye and the Observatory staff photographed it with their cameras as well.

Expert astro-photographers and amateur astronomers came together at the Hanle Dark Sky Reserve between 29 September to 4 October 2024, for the second Star Party.

The unique event was organised by the Indian Institute of Astrophysics (IIA) an autonomous institute of the Department of Science and Technology (DST) in collaboration with Department of Wildlife Protection of UT Ladakh, and Bhabha Atomic Research Centre (BARC) and was attended by more than 45 astronomy enthusiasts from across the country. Hanle and the surrounding region are host to some of the darkest night skies in India. Hence, the Hanle Dark Sky Reserve (HDSR), centred around the Indian Astronomical Observatory, was notified by the Govt. of Ladakh in December 2022, and since then, it has been a major attraction for astro-tourism from across the country.

Using 100 years daily records of the Sun at the Kodaikanal Solar Observatory, astronomers have succeeded in mapping, for the very first time, the variation in the rotation speed of the Sun’s chromosphere, from the equator right up to its polar regions. The research can help give a complete picture of the Sun's inner workings.

This paper was published in the Astrophysical Journal, titled “Equator to Pole Solar Chromospheric Differential Rotation Using Ca-K Features Derived from Kodaikanal Data”, and was authored by Kharayat, Hema (Indian Institute of Astrophysics and M.L.K.P.G. College, Balrampur) and Singh, Jagdev, Priyal, Muthu and Ravindra, B. from Indian Institute of Astrophysics.

Evidence of interaction between a radio jet emitted from special kind of galaxies called Active Galactic Nuclei (AGN) and the surrounding interstellar medium at small spatial scale of about 10 parsecs has been detected for the first time in a dwarf galaxy situated at a distance of about 14 million light years. This finding challenges the hypothesis that only large and massive galaxies jets from which regulate star formation, host AGN powered by massive black holes. Combining data from radio to X-ray wavebands from the galaxy NGC 4395, researchers from Indian Institute of Astrophysics (IIA), an autonomous institute of the Department of Science and Technology (DST) observed evidence for such an interaction at the scale of 10 parsecs, or about 30 light years, around the black hole at the centre of this galaxy.

This study was published in a paper in the Astrophysical Journal, titled “Evidence for Low-power Radio Jet–ISM Interaction at 10 pc in the Dwarf AGN Host NGC 4395”, and was authored by Payel Nandi (lead author), C.S. Stalin, and Ram Sagar from IIA, along with other collaborators spread across institutions in Europe and India.

A new way to probe deeper into the Sun’s secrets has been found by studying the magnetic field at different layers of the solar atmosphere using data from the Kodaikanal Tower Tunnel Telescope. A study led by IIA researchers examined an active region (sunspot) with complex features, including multiple umbrae and a penumbra, through simultaneous observations in the Hydrogen-alpha and Calcium II 8662 Å lines from the Kodaikanal Tower Tunnel telescope. It provides a comprehensive analysis of the line-of-sight (LOS) magnetic field through these simultaneous observations. The results indicate that the Hα line core consistently infers weaker magnetic field strengths than the Ca II 8662 Å line inversions, suggesting that the Hα line samples higher atmospheric layers than the Ca II IR triplet.

Press release published here.

Download the paper from here.