(Press-News.org) Astronomers from Queen's University Belfast have gathered the most direct evidence yet of a supermassive black hole shredding a star that wandered too close. The Queen's astronomers are part of the Pan-STARRS international team, whose discovery has been published in the journal Nature today (Wed, 2 May).
Supermassive black holes, weighing millions to billions times more than the Sun, lurk in the centers of most galaxies. These hefty monsters lie quietly until an unsuspecting 'victim', such as a star, wanders close enough to get ripped apart by their powerful gravitational clutches.
Using a slew of ground and space-based telescopes, a team of astronomers led by Suvi Gezari of The Johns Hopkins University in Baltimore, has identified the victim in this case as a star rich in helium gas. The star resides in a galaxy 2.7 billion light-years away.
The observation yields insights about the harsh environment around black holes and the types of stars swirling around them.
Speaking about the discovery Professor Stephen Smartt of Queen's Astrophysics Research Centre in the School of Maths and Physics said: "Astronomers have spotted these stellar 'murders' before, but this is the first time they can identify the victim.
"What we're seeing is a star being shredded by a monster black-hole in the centre of this distant galaxy. Our own galaxy, the Milky Way has a black hole at its centre, about a million times the mass of the sun. We can see stars whizzing around our Milky Way black hole, but they are too far away from it to be captured.
"In this case a star got too close to the black hole and was sucked right in. We're seeing the star being shredded, heated and destroyed and as it swirls around the black hole. Suvi Gezari, team leader from John Hopkins University in Baltimore, alerted us to something unusual caught by the NASA spacecraft called GALEX, and as our computers sifted through terabytes of Pan-STARRS data, we found the tell-tale signature of the event. We knew it was something weird then."
To find this one event, the team monitored hundreds of thousands of galaxies in ultraviolet light with the Galaxy Evolution Explorer (GALEX), a space-based observatory, and in visible light with the Pan-STARRS1 telescope on the summit of Haleakala, in Hawaii. Pan-STARRS, short for Panoramic Survey Telescope and Rapid Response System, scans the entire night sky for all kinds of transient phenomena, including supernovae.
The team was looking for a bright flare in ultraviolet light from the nucleus of a galaxy with a previously dormant black hole. They found one in June 2010, which was spotted with both telescopes. Both telescopes continued to monitor the flare as it reached peak brightness a month later, and then slowly began to fade over the next 12 months. The brightening event was similar to that of a supernova, but the rise to the peak was much slower, taking nearly one and a half months.
Team leader, Suvi Gezari from The Johns Hopkins University, Baltimore, Md. said: "This is the first time where we have so many pieces of evidence, and now we can put them all together to weigh the perpetrator (the black hole) and determine the identity of the unlucky star that fell victim to it. These observations also give us clues to what evidence to look for in the future to find this type of event."
INFORMATION:
For media enquiries please contact Claire O'Callaghan on +44 (0) 289 097 5391 / (0) 781 441 5451 or at c.ocallaghan@qub.ac.uk
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When it comes to the food used to raise fish in aquaculture "farms," it seems that you may get what you pay for. In a new study,* researchers from the National Institute of Standards and Technology (NIST) and the South Carolina Department of Natural Resources (SCDNR) looked at the health effects of raising farmed fish on a diet incorporating less than the usual amount of fishmeal—a key but expensive component of current commercial fish food products. They learned that reduced fishmeal diets may be cheaper, but the fish were less healthy.
Commercial aquaculture is one ...
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The use of these video recordings ...
As of May 1, 2012, the military has two new drugs in its testing repertoire. Henceforth, service members may be tested for hydrocodone and benzodiazepines, two of the most commonly abused prescription drugs on the market.
Servicemen and servicewomen are randomly tested for drugs at least once a year. A positive test result could mean serious legal complications, putting a servicemember anywhere in the chain of command in need of military drug offense lawyers.
Hydrocodone and Benzodiazepine Part of Expanded Testing Regiment
Hydrocodone is a component in a number ...
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Zebrafish, like rats and mice, are often used by neuroscientists to explore mechanisms controlling behaviour and in the search for new compounds to treat behavioural disease such as addiction, attention deficit disorders or autism.
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Birth injuries, sometimes known as birth traumas, are physical injuries the baby receives while being born. Such injuries can be caused by the process of labor and delivery itself, but they can also be the result of medical malpractice.
Causes of Birth Injuries
Birth injuries are more likely to occur if the birth is a difficult one. A difficult birth is generally caused by the size or position of the baby during labor and delivery. Difficult births usually involve one or more of the following:
- Premature babies (born earlier than 37 weeks)
- Prolonged labor, ...
Recent raids of religious compounds in Texas and British Columbia make clear that polygamy is, to say the least, frowned upon by western governments. But legal questions aside, can polygamy ever be morally permissible?
An article in the latest issue of the journal Ethics makes the case that traditional forms of polygamy are inherently unequal and therefore morally objectionable.
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Following are highlights of presentations that will be given by researchers from NewYork-Presbyterian Hospital/Columbia University Medical Center at the upcoming American Psychiatric Association (APA) annual meeting in Philadelphia (May 5-9, 2012).
Jeffrey Lieberman, MD, the Lawrence C. Kolb Professor and chairman of the Department of Psychiatry at Columbia University Medical Center and NewYork-Presbyterian Hospital/Columbia and director of the New York State Psychiatric Institute, will be officially installed as APA president-elect at the meeting.
To speak with Dr. ...
MAYWOOD, Ill. -- A growing number of health research programs are collaborating with community groups to conduct research. The groups help recruit study participants, obtain informed consent, collect data and provide input on study design and procedures.
But existing programs that educate researchers, community groups and institutional review boards about research ethics "fail to meet the needs of all groups that have a role in community-engaged research," according to an article in the Journal of Empirical Research on Human Research Ethics.
First author of the study ...
