New family of stars discovered in Milky Way shed new light on galaxy's formation

November 22, 2016, Liverpool John Moores University
The image above shows a visible picture of the inner 20 degrees of the Milky Way as seen from Earth (for comparison, the Moon is roughly 1/2 a degree on the sky).  This part of the sky is extremely crowded due to the high density of the central regions of the Galaxy as well as the presence of many stars between Earth and the Galactic centre.  Dark patches are due to absorption of visible light by dense dust clouds.  Overall, the absorption by dust is largest in the centre than anywhere else in the Galaxy.  The cyan circle shows the location of the Galactic centre, and the red stars indicate the positions of the stars newly discovered by APOGEE.  Many of them coincide with regions of high dust absorption, which explains why APOGEE, observing in the infrared, was the first to detect the existence of this new stellar family. Credit: Liverpool John Moores University

An astronomer from LJMU's Astrophysics Research Institute has discovered a new family of stars in the core of the Milky Way Galaxy which provides new insights into the early stages of the Galaxy's formation.

The discovery has shed new light on the origins of – which are concentrations of typically a million stars, formed at the beginning of the Milky Way's history.

LJMU is a member of Sloan Digital Sky Survey - an international collaboration of scientists at numerous institutions. One of the projects of this collaboration is APOGEE (the Apache Point Observatory Galactic Evolution Experiment) which collects infrared data for hundreds of thousands of stars in the Milky Way.

It was through observing stars in the infrared towards the Galactic centre that led to the discovery of a new population of stars, the likes of which had only been seen before inside globular clusters.

This intriguing new family of stars could have possibly belonged to globular clusters that were destroyed during the violent initial formation of the Galactic centre, in which case there would have been about 10 times more globular clusters in the Milky Way in early life than today. This means that a substantial fraction of the old stars inhabiting the inner parts of the Galaxy today may have been initially formed in globular clusters that were later destroyed.

Ricardo Schiavon, lead researcher on the project said:

"This is a very exciting finding that helps us address fascinating questions such as what is the nature of the stars in the inner regions of the Milky Way, how globular clusters formed and what role they played in the formation of the early Milky Way—and by extension the formation of other ."

"The center of the Milky Way is poorly understood, because it is blocked from view by intervening dust. Observing in the infrared, which is less absorbed by dust than visible light, APOGEE can see the center of the Galaxy better than other teams

"From our observations we could determine the chemical compositions of thousands of stars, among which we spotted a considerable number of stars that differed from the bulk of the stars in the inner regions of the Galaxy, due to their very high abundance of nitrogen. While not certain, we suspect that these resulted from globular cluster destruction. They could also be the byproducts of the first episodes of star formation taking place at the beginning of the Galaxy's history. We are conducting further observations to test these hypotheses."

Read the full paper here in the Monthly Notices of the Royal Astronomical Society (MNRAS).

Explore further: Image: Hubble admires a youthful globular star cluster

More information: Ricardo P. Schiavon et al. Chemical tagging with APOGEE: Discovery of a large population of N-rich stars in the inner Galaxy, Monthly Notices of the Royal Astronomical Society (2016). DOI: 10.1093/mnras/stw2162

Related Stories

Image: Hubble admires a youthful globular star cluster

October 31, 2016

Globular clusters offer some of the most spectacular sights in the night sky. These ornate spheres contain hundreds of thousands of stars, and reside in the outskirts of galaxies. The Milky Way contains over 150 such clusters—and ...

Image: A Hubble sky full of stars

August 8, 2016

Located approximately 22,000 light-years away in the constellation of Musca (The Fly), this tightly packed collection of stars—known as a globular cluster—goes by the name of NGC 4833. This NASA/ESA Hubble Space Telescope ...

Virtual Milky Way

November 10, 2016

ESA's Gaia is surveying stars in our Galaxy and local galactic neighbourhood in order to build the most precise 3D map of the Milky Way and answer questions about its structure, origin and evolution.

Image: Hubble views a galaxy fit to burst

July 25, 2016

This NASA/ESA Hubble Space Telescope image reveals the vibrant core of the galaxy NGC 3125. Discovered by John Herschel in 1835, NGC 3125 is a great example of a starburst galaxy—a galaxy in which unusually high numbers ...

Image: Hubble checks out a home for old stars

December 21, 2015

This image, taken with the Wide Field Planetary Camera 2 on board the NASA/ESA Hubble Space Telescope, shows the globular cluster Terzan 1. Lying around 20,000 light-years from us in the constellation of Scorpius (The Scorpion), ...

Recommended for you

Japan space robots start asteroid survey

September 22, 2018

A pair of robot rovers have landed on an asteroid and begun a survey, Japan's space agency said Saturday, as it conducts a mission aiming to shed light on the origins of the solar system.

First to red planet will become Martians: Canada astronaut

September 22, 2018

Astronauts traveling through space on the long trip to Mars will not have the usual backup from mission control on Earth and will need to think of themselves as Martians to survive, Canada's most famous spaceman half-jokingly ...

Three NASA missions return first-light data

September 21, 2018

NASA's continued quest to explore our solar system and beyond received a boost of new information this week with three key missions proving not only that they are up and running, but that their science potential is exceptional. ...

3 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

RNP
3.7 / 5 (3) Nov 23, 2016
Full, open access paper can be found here: https://arxiv.org...3086.pdf
FredJose
1 / 5 (2) Nov 23, 2016
I have come to the realization that words like "sheds new light", "provides clues" and "gives new insight" are euphemisms for "we know squat and have really not made any progress whatsoever in solving the issue of stars forming by themselves".
RNP
3.7 / 5 (3) Nov 23, 2016
@FredJose
Your unsupported and ill-informed "realizations" are of no value whatsoever.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.