heic1903 — Photo Release

Hubble fortuitously discovers a new galaxy in the cosmic neighbourhood

Astronomers using the NASA/ESA Hubble Space Telescope to study some of the oldest and faintest stars in the globular cluster NGC 6752 have made an unexpected finding. They discovered a dwarf galaxy in our cosmic backyard, only 30 million light-years away. The finding is reported in the journal Monthly Notices of the Royal Astronomical Society: Letters.

An international team of astronomers recently used the NASA/ESA Hubble Space Telescope to study white dwarf stars within the globular cluster NGC 6752. The aim of their observations was to use these stars to measure the age of the globular cluster, but in the process they made an unexpected discovery.

In the outer fringes of the area observed with Hubble’s Advanced Camera for Surveys a compact collection of stars was visible. After a careful analysis of their brightnesses and temperatures, the astronomers concluded that these stars did not belong to the cluster — which is part of the Milky Way — but rather they are millions of light-years more distant.

Our newly discovered cosmic neighbour, nicknamed Bedin 1 by the astronomers, is a modestly sized, elongated galaxy. It measures only around 3000 light-years at its greatest extent — a fraction of the size of the Milky Way. Not only is it tiny, but it is also incredibly faint. These properties led astronomers to classify it as a dwarf spheroidal galaxy.

Dwarf spheroidal galaxies are defined by their small size, low-luminosity, lack of dust and old stellar populations [1]. 36 galaxies of this type are already known to exist in the Local Group of Galaxies, 22 of which are satellite galaxies of the Milky Way.

While dwarf spheroidal galaxies are not uncommon, Bedin 1 has some notable features. Not only is it one of just a few dwarf spheroidals that have a well established distance but it is also extremely isolated. It lies about 30 million light-years from the Milky Way and 2 million light-years from the nearest plausible large galaxy host, NGC 6744. This makes it possibly the most isolated small dwarf galaxy discovered to date.

From the properties of its stars, astronomers were able to infer that the galaxy is around 13 billion years old — nearly as old as the Universe itself. Because of its isolation — which resulted in hardly any interaction with other galaxies — and its age, Bedin 1 is the astronomical equivalent of a living fossil from the early Universe.

The discovery of Bedin 1 was a truly serendipitous find. Very few Hubble images allow such faint objects to be seen, and they cover only a small area of the sky. Future telescopes with a large field of view, such as the WFIRST telescope, will have cameras covering a much larger area of the sky and may find many more of these galactic neighbours.

Notes

[1] While similar to dwarf elliptical galaxies in appearance and properties, dwarf spheroidal galaxies are in general approximately spherical in shape and have a lower luminosity.

More information

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

The results were presented in the letter The HST Large Programme on NGC 6752. I. Serendipitous discovery of a dwarf galaxy in background, published in the journal Monthly Notices of the Royal Astronomical Society: Letters.

The international team of astronomers that carried out this study consists of L. R. Bedin (INAF-Osservatorio Astronomico di Padova, Italy), M. Salaris (Liverpool John Moores University, UK), R. M. Rich (University of California Los Angeles, USA), H. Richer (University of British Columbia), J. Anderson (Space Telescope Science Institute, USA), B. Bettoni (INAF-Osservatorio Astronomico di Padova, Italy), D. Nardiello (Università di Padova, Italy), A. P. Milone (Università di Padova, Italy), A. F. Marino (Università di Padova, Italy), M. Libralato (Space Telescope Science Institute, USA), A. Bellini (Space Telescope Science Institute, USA), A. Dieball (University of Bonn, Germany), P. Bergeron (Université de Montréal, Canada), A. J. Burgasser (University of California San Diego, USA), D. Apai (University of Arizona, USA)

Image credit: NASA, ESA, Bedin et al.

Links

Contacts

L. R. Bedin

INAF-Osservatorio Astronomico di Padova

Padua, Italy

Tel: +49 8293 413

Email: luigi.bedin@oapd.inaf.it

Mathias Jäger

ESA/Hubble, Public Information Officer

Garching, Germany

Tel: +49 176 62397500

Email: mjaeger@partner.eso.org</s>While inspecting a known globular cluster, a team of astronomers began to notice that some of its stars didn’t seem to belong. Investigating further, they realized the anomalous stars were part of a nearby galaxy—one previously unknown to us.



One moment you’re investigating a globular cluster, and the next you’re unexpectedly writing a research paper about something else entirely, namely the discovery of previously unknown dwarf spheroidal galaxy. But that’s how it goes sometimes, and the authors of the new study, published this week in the Monthly Notices of the Royal Astronomical Society, couldn’t be happier.

“It was definitely a surprise!” exclaimed Luigi Bedin, an astronomer at INAF-Osservatorio Astronomico di Padova in Italy and the lead author of the new study. “We knew it was something atypical.”

Named Bedin I in honor of its discoverer, the freshly spotted galaxy is definitely not ordinary. It’s freakishly small, dim, and very, very old. And remarkably, it’s sitting right next door, cosmically speaking: At 30 million light-years away, it’s considered part of our Local Group of galaxies. (To give you an idea of scale, the Milky Way itself measures 105,000 light-years across.)

Bedin 1 is located in the Pavo constellation, which is visible in the Northern Hemisphere. The diminutive galaxy hasn’t been detected until now because it’s obscured by NGC 6752, the globular cluster that Bedin’s team was investigating. Specifically, they were analyzing white dwarf stars within NGC 6752 to measure the age of the cluster, which is located approximately 17,000 light-years from the center of the Milky Way. Using the NASA/ESA Hubble Space Telescope, the astronomers began to notice that some stars along the outer fringes of the globular cluster were out of place, leading to the accidental discovery.

“The temperature and luminosity of these stars suggested they were more distant,” Bedin told Gizmodo. “And they were too loose and too far away from other nearby galaxies.”

The astronomers quickly realized they were looking at a previously undetected galaxy—a compact collection of ancient stars measuring 3,000 light-years across and situated 2,300 times further away than globular cluster NGC 6752. Bedin I was classified as a dwarf spheroidal galaxy owing to its small size (it’s about 1/35th the diameter of the Milky Way), low luminosity, lack of dust, and population of old stars. To date, some 36 galaxies of this type have been documented in the Local Group of galaxies, according to a Hubble release about the discovery.

“Had the galaxy been 10 times further away, it would have been much harder to detect,” said Bedin. “It would’ve been outside our Local Group.”

Bedin I was dated to around 13 billion years old; its oldest stars are no longer burning hydrogen—a tell-tale sign of its extreme age, explained Bedin. This dwarf galaxy formed during the earliest stages of the Universe, so it’s considered a cosmological fossil. Remarkably, it formed during the first hundreds of millions of years after the Big Bang. Its discovery confirms suspicions that some of the Universe’s oldest galaxies are nearby. But as this discovery also shows, they’re rather hard to spot, mostly because they’re so small and dim. 



Not only is this dwarf galaxy old, it’s also remarkably isolated and undisturbed. Bedin I has been floating through the cosmos with impunity for billions of years, making it an excellent target for future investigations. The discovery of this isolated galaxy could “put constraints on models of how the galaxy we see today did form,” said Bedin.

As a final note, Bedin said he pleased with the galaxy’s new name, saying it was “nice to adopt a nickname from one of its discoverers instead of an anonymous identification based on its coordinates.” Hard to fault him on that! Those dreadful numerical designations, while utilitarian, are often quite silly. No harm in giving catchy names to cool things, and by consequence, honoring the researchers involved.</s>sing the NASA/ESA Hubble Space Telescope, scientists have discovered a new dwarf galaxy relatively near the Milky Way.

The discovery was made by an international team of astronomers who had been utilizing the Hubble to observe some of the oldest and faintest white dwarf stars within the globular cluster NGC 6752. Their aim was to measure the age of the cluster by using these stars, but they unexpectedly found a dwarf galaxy in our cosmic backyard.

The scientists observed a compact collection of stars in the outer edges of the area observed with Hubble's Advanced Camera for Surveys. They analyzed the brightness and temperatures of the stars and later found that they did not belong to the globular cluster, which is part of the Milky Way. Instead, they were actually about 30 million light-years away.

Dubbed Bedin 1 by the astronomers who discovered it, the dwarf galaxy has been described as modestly sized and elongated. Our newly discovered cosmic neighbor is very faint and tiny, measuring only about 3,000 light-years at its greatest extent, which is just a fraction of the size of the Milky Way galaxy. Due to these, scientists have determined that it is a dwarf spheroidal galaxy, according to a report published in the journal Monthly Notices of the Royal Astronomical Society: Letters.

Dwarf spheroidal galaxies all have small sizes, low-luminosities and lack dust and old stars. Within the Local Group of Galaxies, there are about 36 of the dwarf spheroidal type, and among them, 22 are satellite galaxies of the Milky Way.

Bedin 1 has some features that make it stand out from other dwarf spheroidal galaxies, which are not uncommon. Bedin 1 is very isolated and is also one of the very few of its type that have a well-established distance. Perhaps the most isolated small dwarf galaxy discovered so far, the Bedin 1 is located 30 million light-years away from the Milky Way galaxy and two million light-years from NGC 6744, its nearest plausible galaxy host.

Scientists also gleaned from its stars' properties that the galaxy might be nearly the same age as the universe itself at 13 billion years old.

This article was first published in IBTimes US. Permission required for reproduction.</s>The fascinating galaxy lies 30 million light-years away, and could be 'the most isolated small dwarf galaxy discovered to date.'

Astronomers have just made an incredible discovery while scouring the sky with the Hubble Space Telescope. Hidden behind a distant star cluster, the scientists uncovered a never-before-seen dwarf galaxy located right in our “cosmic backyard.”

The news comes from NASA, which announced earlier today that the newfound galaxy is a “dwarf spheroidal galaxy that is as old as the universe.” The dwarf galaxy is very ancient, dating back to 13 billion years ago, and is located some 30 million light-years away — a stone’s throw in cosmic terms.

According to the Hubble Space Telescope website, the dwarf galaxy was found purely by chance. The credit goes to an international team of astronomers led by L.R. Bedin from the INAF-Astronomical Observatory of Padua in Italy. The scientists stumbled upon the dwarf galaxy while observing a globular star cluster called NGC 6752, which lies 13,000 light-years away in the halo of the Milky Way galaxy.

As the Inquisitr previously reported, globular clusters are spherical and extremely dense stellar bundles crammed with thousands of ancient stars that date back to the early days of the universe.

While looking at NGC 6752, the team initially spotted an odd group of stars that didn’t seem to belong to the globular cluster. After analyzing their brightness and temperature, the astronomers realized that the stars weren’t part of NGC 6752, but were actually located behind it — approximately 2,300 times farther out into the cosmos.

The newly discovered dwarf galaxy has been dubbed Bedin 1. Nestled right on the doorstep of the Milky Way galaxy, the tiny Bedin 1 sports an elongated shape and measures just 3,000 light-years at its greatest extent. That puts the dwarf galaxy at just a fraction of the size of the Milky Way, barely one-thirtieth of our galaxy’s diameter.

In addition to being very old and very small, Bedin 1 is also incredibly faint. Compared to the Milky Way, its luster is 1,000 times dimmer. All of these characteristics have earned it the classification of dwarf spheroidal galaxy — a group of small galaxies with “low-luminosity, lack of dust, and old stellar populations,” explains the Hubble website.

While this type of galaxy might be fairy common, Bedin 1 is one of the most fascinating of the bunch. The tiny galaxy ranks among a handful of dwarf spheroidals with a well-established distance. At the same time, the dwarf galaxy is extremely isolated — it lies 2 million light-years from the nearest major galaxy that might host it as a satellite, a large spiral galaxy called NGC 6744.

The video below uses real Hubble data to recreate the journey to Bedin 1 by way of an animation, one which shows the cosmic flight through the NGC 6752 globular cluster and all the way to the dwarf galaxy hidden behind it.

The uncommon features of Bedin 1 make the dwarf galaxy particularly interesting for study, said NASA.

The paper describing this amazing find can be read in the Monthly Notices of the Royal Astronomical Society: Letters.</s>If there's one thing that most of us don't appreciate about astronomy, it's that everything we know about the Universe has been observed from more or less the same place: here. Even the Hubble space telescope, still orbiting Earth after almost 29 years of incredible service, is restricted by its line of sight.

So it should come as no surprise that, now and again, Hubble finds something lurking behind something else. That's exactly what has just happened, with the space telescope 'accidentally' finding an ancient galaxy, nicknamed Bedin 1, in our cosmic neighborhood while looking at something else entirely.

It was photographing the globular star cluster NGC 6752, which lies about 13,000 light-years away in the halo of our own galaxy, the Milky Way. Globular clusters are dense star clusters that orbit galaxies, somewhat mysteriously. NGC 6752 is in the constellation of Pavo, the peacock, which is most easily seen from the northern hemisphere from June to October.

NGC 6752 is the third brightest of the 'the big three' globular clusters visible to us, the other two being Omega Centauri and 47 Tucanae. Despite not having a popular name, NGC 6752 is a popular subject for astronomers and has previously appeared on Astronomy Picture of the Day.

The astronomers that fortuitously discovered Bedin 1 were on a hunt for white dwarf stars in an effort to measure the age ofNGC 6752.

Bedin 1 is a 13 billion-year-old dwarf spheroidal galaxy, which is defined as a galaxy with a maximum of several billion stars. It measures only around 3,000 light-years at its greatest extent (almost 1/30th the diameter of the Milky Way), and it is roughly a thousand times dimmer than our Milky Way. There are 36 dwarf spheroidal galaxies in our 'Local Group' of galaxies, 22 of which are satellite galaxies of the Milky Way. The Local Group is a collection of 54 galaxies, one of which is the Milky Way.

How far away is Bedin 1?

Bedin 1 is just 30 million light-years away. That's about 2,300 times farther than the foreground globular cluster NGC 6752, but in cosmic terms, that's pretty close to the Milky Way.

Since Bedin 1 is nearly as old as the universe itself and completely isolated, it's seemingly not been affected greatly by the gravity if other galaxies, leading the astronomers behind this discovery to describe it as 'the astronomical equivalent of a living fossil from the early universe'. "Not only is it one of just a few dwarf spheroidals that have a well-established distance, but it is also extremely isolated," they say. "It lies about 30 million light-years from the Milky Way and two million light-years from the nearest plausible large galaxy host, NGC 6744. This makes it possibly the most isolated small dwarf galaxy discovered to date."

Reported today in the journal Monthly Notices of the Royal Astronomical Society: Letters, the astronomers also describe it as of 'broad interest to complete the census of galaxies in the local Universe'.

It's hoped that future telescopes with a large field of view, such as the WFIRST telescope, will have cameras covering a much larger area of the sky, which may help find many more galactic neighbors like Bedin 1.

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Follow me on Twitter @jamieacarter, @TheNextEclipse or read my other Forbes articles via my profile page.</s>Humanity is getting pretty good at looking deep into space. We've peered back over 13 billion light-years. We've seen - actually seen - two neutron stars colliding. We're homing in on fast radio bursts, and we're about to see, for the first time, the event horizon of a black hole. But there are still some surprises out there, even in our own corner of the Universe.

While taking observations of a nearby globular cluster, the Hubble Space Telescope accidentally caught a previously unseen galactic photobomber in the distance. The newly discovered galaxy has been named Bedin I - and it's nearly as old as the Universe.

The mission was to look for the faintest stars in NGC 6752, a globular cluster 13,000 light-years away within the Milky Way's halo, where a bunch of globular clusters just hang out.

But in the distance - around 30 million light-years away, roughly 2,300 times more distant than the star they were aiming at - Bedin I was lurking. (The Local Group is about 10 million light-years across; if you think of it like a block, 30 million is like being in the same cosmic town.)

"We report the discovery of Bedin I, a dwarf spheroidal galaxy too faint and too close to the core of NGC 6752 for detection in earlier surveys," the researchers wrote in their letter describing the find.

"We have discovered this object serendipitously with extraordinarily deep Hubble Space Telescope images obtained for the purpose of investigating the white dwarf cooling sequence of the globular cluster NGC 6752."

Bedin I is tiny, and isolated, and ancient. It's just 3,000 light-years across, compared to the Milky Way's estimated 100,000 light-years, and it's roughly 1,000 times fainter. It's been classified as a dwarf spheroidal galaxy.

Usually, dwarf spheroidal galaxies are companions to larger galaxies or systems, but not Bedin I. It is 2 million light-years from the closest galaxy that could be considered a host, spiral galaxy NGC 6744.

Based on the light it emits, the team was able to determine that the galaxy is very low in metals. Since heavier elements, such as metals, were created in stars and only propagated throughout the Universe after those stars died, this indicates that Bedin I has a very old population of stars.

The team estimated that the galaxy is around 13 billion years old - add just 0.8 billion years, and it would be as old as the Universe itself. The low metal content implies that Bedin I came into being in a burst, and hasn't had any new star formation since.

This means it's a sort of cosmic 'living fossil' or time capsule, preserving the conditions of the early Universe.

Given that Bedin I is so far away, and so faint, and obscured by closer stars, it's amazing that it was discovered at all - and by the Hubble Space Telescope, which has been in operation for nearly 30 years now. We hope it keeps going for many more.

The team's paper has been published in the Monthly Notices of the Royal Astronomical Society: Letters.</s>There’s no shortage of interesting things to see in our own galaxy, but astronomers love finding new galactic neighbors as well. Observing other galaxies can teach scientists a lot about how the massive structures form, live, and die.

Using images from the Hubble Space Telescope, researchers studying distant, dim stars accidentally stumbled upon something they hadn’t anticipated: An entirely undocumented galaxy sitting around 30 million light-years from Earth. News of the discovery was published in Monthly Notices of the Royal Astronomical Society.

The astronomers who discovered this new galaxy were originally doing a survey of a cluster known as NGC 6752. These faint stars were being studied so that scientists could better gauge how old the cluster was as a whole, but that’s when they noticed what appeared to be a galaxy that had yet to be documented.

“Our newly discovered cosmic neighbour, nicknamed Bedin 1 by the astronomers, is a modestly sized, elongated galaxy,” explains the official Hubble website. “It measures only around 3000 light-years at its greatest extent — a fraction of the size of the Milky Way. Not only is it tiny, but it is also incredibly faint. These properties led astronomers to classify it as a dwarf spheroidal galaxy.”

Further observations led the astronomers to deduce that the galaxy is roughly 13 billion years old, making it roughly as old as the Milky Way. However, its remote location and the fact that it’s not near any other galaxies has led researchers to label it “a living fossil from the early Universe.”

The tiny galaxy is truly off on its own, and is roughly two million light years from the nearest large galaxy, so it’s something of a time capsule that dates back billions and billions of years. It’s too far away to study in any great detail with modern technology, but its accidental discovery is definitely one for the books.</s>Astronomers using the NASA/ESA Hubble Space Telescope to study some of the oldest and faintest stars in the globular cluster NGC 6752 have made an unexpected finding.

They discovered a dwarf galaxy in our cosmic backyard, only 30 million light-years away.

The finding is reported in the journal Monthly Notices of the Royal Astronomical Society: Letters.

An international team of astronomers recently used the NASA/ESA Hubble Space Telescope to study white dwarf stars within the globular cluster NGC 6752. The aim of their observations was to use these stars to measure the age of the globular cluster, but in the process they made an unexpected discovery.

In the outer fringes of the area observed with Hubble’s Advanced Camera for Surveys a compact collection of stars was visible. After a careful analysis of their brightnesses and temperatures, the astronomers concluded that these stars did not belong to the cluster — which is part of the Milky Way — but rather they are millions of light-years more distant.

Our newly discovered cosmic neighbor, nicknamed Bedin 1 by the astronomers, is a modestly sized, elongated galaxy. It measures only around 3000 light-years at its greatest extent — a fraction of the size of the Milky Way. Not only is it tiny, but it is also incredibly faint. These properties led astronomers to classify it as a dwarf spheroidal galaxy.

Dwarf spheroidal galaxies are defined by their small size, low-luminosity, lack of dust and old stellar populations [1]. 36 galaxies of this type are already known to exist in the Local Group of Galaxies, 22 of which are satellite galaxies of the Milky Way.

While dwarf spheroidal galaxies are not uncommon, Bedin 1 has some notable features. Not only is it one of just a few dwarf spheroidals that have a well-established distance but it is also extremely isolated. It lies about 30 million light-years from the Milky Way and 2 million light-years from the nearest plausible large galaxy host, NGC 6744. This makes it possibly the most isolated small dwarf galaxy discovered to date.

From the properties of its stars, astronomers were able to infer that the galaxy is around 13 billion years old — nearly as old as the Universe itself. Because of its isolation — which resulted in hardly any interaction with other galaxies — and its age, Bedin 1 is the astronomical equivalent of a living fossil from the early Universe.

The discovery of Bedin 1 was a truly serendipitous find. Very few Hubble images allow such faint objects to be seen, and they cover only a small area of the sky. Future telescopes with a large field of view, such as the WFIRST telescope, will have cameras covering a much larger area of the sky and may find many more of these galactic neighbors.</s>Imagine you have a neighbor living down the block in a house you never noticed before because it was tucked in behind some apartments. The human residents of the Milky Way galaxy are now saying hi to a neighboring galaxy we didn't even know existed.

A team of astronomers serendipitously discovered the galaxy, nicknamed Bedin 1, while studying a globular star cluster known as NGC 6752.

"In a celestial game of 'Where's Waldo?' Hubble's sharp vision uncovered a never-before-seen dwarf galaxy located far behind the cluster's crowded stellar population," NASA said on Thursday.

NASA says the dim galaxy is in our "cosmic backyard" at just 30 million light-years away. Bedin 1 is a fraction of the size of the Milky Way and is classified as a dwarf spheroidal galaxy.

Astronomers estimate Bedin 1's age at about 13 billion years and say it's been isolated from interactions with other galaxies. NASA likens it to the "astronomical equivalent of a living fossil from the early universe."

"Very few Hubble images allow such faint objects to be seen, and they cover only a small area of the sky," said the European Space Agency.

The Hubble Space Telescope is a joint project between NASA and ESA. The researchers published their findings in the journal Monthly Notices of the Royal Astronomical Society: Letters.
Astronomers announce, through the Monthly Notices of the Royal Astronomical Society journal, the accidental discovery of dwarf spheroidal galaxy Bedin I in the Pavo constellation in September 2018.