Previously unseen star formation in Milky Way detected in new study
Bengaluru, July 23: An international team of astronomers has carried out an extensive new survey of the Milky Way, revealing previously unseen signatures with unprecedented sensitivity and details that hint at how stars form and die, complex processes that have fascinated researchers for centuries.
The results were published in a series of papers in 'Astronomy & Astrophysics' by the team, which includes scientists from the Indian Institute of Science (IISc) and the Indian Institute of Space Science and Technology (IIST).
(Photo: Brunthaler et al., Sophia Dagnello, NRAO/AUI/NSF)GLOSTAR image, using data from both the VLA and the Effelsberg radio telescope, shows a segment of the Milky Way's disk, revealing previously unseen tracers of massive star formation. Some of these features are identified in this version of the image.
The data for the survey, which spanned a large part of the Milky Way, was gathered using two powerful radio telescopes: the Karl G Jansky Very Large Array (VLA) at the National Radio Astronomy Observatory, USA, and theEffelsberg100-m radio telescope operated by the Max Planck Institute for Radio Astronomy Germany, as part of the GLOSTAR (Global View on Star formation in the Milky Way) project.
Nirupam Roy, Assistant Professor at the Department of Physics and Rohit Dokara, his former undergraduate student from IISc, as well as Jagadheep D Pandian, Associate Professor at the Department of Earth and Space Sciences in IIST are among the Indian scientists who are part of the GLOSTAR project, Bengaluru-based IISc said in a statement on Friday.
Dokara, now a PhD student at MPIfR, is the first author on one of the papers that reports the detection of new supernova remnants (SNRs) structures born from the explosive death of massive stars in our galaxy.
Previous surveys have detected only about one-third of the expected number of SNRs in the Milky Way (which is nearly 1000), according to the statement.
The GLOSTAR team has now discovered 80 new SNR candidates in the VLA data alone,with more expected to be identified from the combined Effelsberg and VLA data.
They were also able to confirm the presence of 77 previously discovered SNR candidates and reclassify a few that were misidentified.
This is impressive, considering that the northern telescopes utilised by GLOSTAR are able to see only half of the inner regions of the Milky Way, it said.
"This is an important step to solve this long-standing mystery of the missing supernova remnants," said Dokara.
The researchers were also able to detect other traces of star formation.
One of them, for example, is radio emission from methanol molecules in a nearby large star-forming complex 'Cygnus X.'
These are typically emitted from massive stars in very early stages of formation.
The team was also able to detect dense pockets of ionised hydrogen, another tell-tale sign of the presence of massive young stars.
Young stars are usually surrounded by thick clouds of dust and gas.
"Because visible light gets absorbed in this dense cloud around stars, most of the optical telescopes dont reveal much.
What people look for, instead, are radio emissions," explained Roy, who has previously worked at both NRAO and MPIfR.
"Since the GLOSTAR survey detects a wide range of radio emission such as that from methanol molecules to ionised hydrogen, it is able to probe the formation of massive stars from very early to relatively late stages, which is important to get a complete picture of star formation in the Milky Way," added Pandian, who has also previously worked at MPIfR.
The Effelsberg radio telescope is a single large dish spanning 100 m in diameter, capable of detecting large-scale structures, whereas the VLA is a collection of small antennas which work together as an interferometer to capture the details at high resolution.
The data pooled from both telescopes helped the researchers paint a more comprehensive picture of different astrophysical objects in the region.
"This clearly demonstrates that the Effelsberg telescope is still very crucial, even after 50 years of operation," said Andreas Brunthaler of MPIfR, project leader and first author of the survey's overview paper.
Karl Menten, the Director of MPIfR, who initiated GLOSTAR, added: "Its great to see the beautiful science resulting from two of our favourite radio telescopes joining forces."
Both Pandian and Roy currently maintain Max Planck-India Partner Groups with Menten to continue the close collaboration and, in particular, to expand the scope of the GLOSTAR project.
Other members of the research team include scientists from MPIfR and NRAO, and collaborators from institutions in the UK, South Africa, Mexico, France and Australia.
With observations and analysis ongoing, more results are expected to be published over time, it was stated.
New extensive survey of #MilkyWay using powerful radio telescopes reveals previously unseen details that hint at how stars form and die. The team includes researchers from IISc, @IIST_Trivandrum, MPIfR, @TheNRAO & other collaborators.https://t.co/URLPyRrckg pic.twitter.com/plwYKLiPr2
— IISc Bangalore (@iiscbangalore) July 23, 2021
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SRH knocked out of play-off race after washout against DC
Hyderabad, May 5 (PTI): Sunrisers Hyderabad were eliminated from the play-offs race after their Indian Premier League fixture against Delhi Capitals was called off due to heavy rain following the first innings here on Monday.
Pat Cummins-led SRH pace attack ran through the DC batting line-up to limit the visitors to 133/7 before rain dashed the slim hopes of the home team. Both teams shared a point each for the abandoned game.
With 13 points from 11 games, DC remain in contention for a top-four spot.
After reaching the final last year, it was a season to forget for SRH who could not replicate their ballistic run of 2024 with the bat. Having collected only seven points from 11 matches, SRH will now be playing for pride.
Chennai Super Kings and Rajasthan Royals were already eliminated from the competition.
Before rain lashed the Rajiv Gandhi Stadium, the hosts put up a clinical effort with the ball and were on course for only their fourth win of the season until rain arrived, creating large puddles of water on the outfield. The match officials decided to call off the game at 11.10 pm local time.
The shot selection of Delhi Capitals' batters contributed to their downfall after being put in to bat.
They were left reeling at 29 for five in 7.1 overs with captain Cummins causing the maximum damage.
Cummins had Karun Nair caught behind on the very first ball of the match with a good length ball around the off-stump. It was a rather loose shot from the DC batter first up.
Faf du Plessis departed in Cummins' following over, a failed attempt to put the relentless Australian away for a boundary. Not getting any loose ball from Cummins, the South Africa went for a pull on the charge only to be caught by the wicket-keeper.
Cummins' third victim was Abhishek Porel who was caught after mistiming a flick.
Harshal Patel and Jaydev Unadkat then got into the act by dismissing Axar Patel and K L Rahul respectively. The in-form Rahul went for a drive on the up but ended up edging it to Ishan Kishan behind the stumps.
It was one way traffic until Tristian Stubbs (41 not out off 36) and impact player Ashutosh Sharma (41 off 26) combined to take DC to a respectable total. They shared a 66-run stand off 45 balls.
Sharma was able to break the shackles by depositing leg-spinner Zeeshan Ansari for a couple of sixes over long-on in the 15th over.
Stubbs did not look as comfortable as Sharma in the middle but managed to provide much needed support to the latter. The South African could find only four boundaries with the last one coming off the final ball of the innings.
🚨 News 🚨
— IndianPremierLeague (@IPL) May 5, 2025
Match 55 between @SunRisers and @DelhiCapitals has been called off due to wet outfield.
Both teams share a point each.
Scorecard ▶ https://t.co/1MkIwk4VNE
#TATAIPL | #SRHvDC pic.twitter.com/VnVZWjsjGJ
