Hubble fortuitously discovers a new galaxy in the cosmic neighbourhood

The accidentally discovered galaxy Bedin I

Bedin 1 in NGC 6752

Globular cluster NGC 6752

Wide-field view of NGC 6752 (ground-based view)


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Zooming in on NGC 6752 and Bedin 1

Zooming in on NGC 6752 and Bedin 1

Flight to Bedin 1
Flight to Bedin 1


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


Contact

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


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Earliest evidence of beer making in UK found

Experts working on Highways England’s £1.5bn upgrade of the A14 in Cambridgeshire have uncovered what is believed to be evidence of the first beer brewed in the UK.

Earliest evidence of beer making in UK found
Fragments of residue from early beer-making process [Credit: (c) MOLA Headland Infrastructure]

The tell-tale signs of the Iron Age brew, potentially from as far back as 400 BC, were uncovered in tiny fragments of charred residues from the beer making process from earth excavated with other archaeological finds.

Further finds show the locals also had a taste for porridge and bread as well as beer. The discoveries are the latest on the road project where previous finds include woolly mammoths, abandoned villages, and burials.

Dr Steve Sherlock, Highways England archaeology lead for the A14, said: «The work we are doing on the A14 continues to unearth incredible discoveries that are helping to shape our understanding of how life in Cambridgeshire, and beyond, has developed through history.»

«It’s a well-known fact that ancient populations used the beer making process to purify water and create a safe source of hydration, but this is potentially the earliest physical evidence of that process taking place in the UK. This is all part of the work we are doing to respect the areas cultural heritage while we deliver our vital upgrade for the A14.»

A team of up to 250 archaeologists led by experts from MOLA Headland Infrastructure has been working on the project, investigating 33 sites across 360 hectares.

MOLA Headland archaeobotanist Lara Gonzalez, who came across the latest fascinating evidence, said: «I knew when I looked at these tiny fragments under the microscope that I had something special. The microstructure of these remains had clearly changed through the fermentation process and air bubbles typical of those formed in the boiling and mashing process of brewing.»

«It’s like looking for a needle in a haystack but as an archaeobotanist it’s incredibly exciting to identify remains of this significance and to play a part in uncovering the fascinating history of the Cambridgeshire landscape.»

Earliest evidence of beer making in UK found
Left – microscopic sample on the showing what is believed the be the earliest evidence of beer making in the UK.
Right – evidence of bread making [Credit: (c) Highways England courtesy of MOLA Headland]

«The porous structures of these fragments are quite similar to bread, but through microscopic study, it’s possible to see that this residue is from the beer-making process as it shows evidence of fermentation and contains larger pieces of cracked grains and bran but no fine flour. Further analysis into the fermentation process involved in brewing will hopefully tell us more.»

The A14 is a key route between the east coast and the midlands, and Highways England is upgrading a 21-mile section between Cambridge to Huntingdon, which will speed up journeys by up to 20 minutes. Finds so far have included 40 pottery kilns, 342 burials, a Roman supply depot, rare Roman coins from the third century, three Anglo Saxon villages, an abandoned Medieval village.

When archaeological features are excavated, soil samples are collected and sent back to a laboratory for archaeobotanists to examine. These samples hold tiny but vital evidence that can shape our understanding of how, and where, people have cultivated crops, providing tantalising clues about our food, drink and occasionally clothing, in the distant past.

Roger Protz, lecturer, author of more than 20 books on beer including IPA – A Legend in Our Time, and former editor of the Campaign for Real Ale’s Good Beer Guide, said: «East Anglia has always been of great importance to brewing as a result of the quality of the barley that grows there. It’s known as maritime barley and is prized throughout the world.»

«When the Romans invaded Britain they found the local tribes brewing a type of beer called curmi. As far as is known, it was made from grain, but no hops were used: hops didn’t come into use in Britain until the 15th century, and there was much opposition to hops from many traditional brewers, who used herbs and spice to balance the sweetness of the malt.»

«In the late 1990s scientists at Cambridge University used a translation of a recipe for beer brewed in Ancient Egypt that was made from grain and dates. I tasted the beer and it was surprisingly ‘beery’. A brewery in Ghent, Belgium, called Gruut produces beers using medieval recipes and flavours the beers with the likes of ivy, ginger, bog myrtle and peppercorns. Again, the end products are remarkably like modern beers. The Romans may have made beer – perhaps when supplies of wine ran out. Excavations in the old Roman part of St Albans – Verulamium – found a malt kiln.»

Credit: Highways England [January 31, 2019]

TANN

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