Is a supermassive black hole is hidden in the Large Magellanic Cloud?
Based on the motions of a number of runaway stars on the edge of the Milky Way that are moving so fast they will leave the galaxy, astronomers believe that many were accelerated not by the galaxy’s own central supermassive black hole but a previously undetected supermassive black hole at the center of the Large Magellanic Cloud, one of the Milky Ways nearby dwarf galaxies.
To make this discovery, researchers traced the paths with ultra-fine precision of 21 stars on the outskirts of the Milky Way. These stars are traveling so fast that they will escape the gravitational clutches of the Milky Way or any nearby galaxy. Astronomers refer to these as “hypervelocity” stars.
Similar to how forensic experts recreate the origin of a bullet based on its trajectory, researchers determined where these hypervelocity stars come from. They found that about half are linked to the supermassive black hole at the center of the Milky Way. However, the other half originated from somewhere else: a previously-unknown giant black hole in the Large Magellanic Cloud (LMC).
You can read the paper here [pdf]. This result was made possible by the very precise location and velocity data of over a billion stars measured by Europe’s Gaia satellite.
Based on the available data, the scientists estimate (with great uncertainty) the mass of this supermassive black hole, which the scientists have dubbed LMC* (pronounced “LMC star”), to be about 600,000 times the mass of the Sun, quite big but significantly less than the mass of the Milky Way’s central black hole, Sagittarius A* (pronounced “A-star”), which is estimated to be about 4.3 million times the mass of the Sun.
The mystery to solve now is why this super massive black hole is so quiet. It has literally emitted no obvious energy in any wavelength in the past seven decades, since ground- and space-based telescopes went into operation capable of detecting such emissions. Even the relatively inactive supermassive black hole at the Milky Way’s center, Sagittarius A* (pronounced “A-star”) emits distinct radio energy that the first radio telescopes were able to detect almost immediately.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Based on the motions of a number of runaway stars on the edge of the Milky Way that are moving so fast they will leave the galaxy, astronomers believe that many were accelerated not by the galaxy’s own central supermassive black hole but a previously undetected supermassive black hole at the center of the Large Magellanic Cloud, one of the Milky Ways nearby dwarf galaxies.
To make this discovery, researchers traced the paths with ultra-fine precision of 21 stars on the outskirts of the Milky Way. These stars are traveling so fast that they will escape the gravitational clutches of the Milky Way or any nearby galaxy. Astronomers refer to these as “hypervelocity” stars.
Similar to how forensic experts recreate the origin of a bullet based on its trajectory, researchers determined where these hypervelocity stars come from. They found that about half are linked to the supermassive black hole at the center of the Milky Way. However, the other half originated from somewhere else: a previously-unknown giant black hole in the Large Magellanic Cloud (LMC).
You can read the paper here [pdf]. This result was made possible by the very precise location and velocity data of over a billion stars measured by Europe’s Gaia satellite.
Based on the available data, the scientists estimate (with great uncertainty) the mass of this supermassive black hole, which the scientists have dubbed LMC* (pronounced “LMC star”), to be about 600,000 times the mass of the Sun, quite big but significantly less than the mass of the Milky Way’s central black hole, Sagittarius A* (pronounced “A-star”), which is estimated to be about 4.3 million times the mass of the Sun.
The mystery to solve now is why this super massive black hole is so quiet. It has literally emitted no obvious energy in any wavelength in the past seven decades, since ground- and space-based telescopes went into operation capable of detecting such emissions. Even the relatively inactive supermassive black hole at the Milky Way’s center, Sagittarius A* (pronounced “A-star”) emits distinct radio energy that the first radio telescopes were able to detect almost immediately.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
I don’t even need to say it, do I? It’s the 21st century. If you’re going to come up with ridiculous names, move beyond ASCII. Why not LMC😡?
I was afraid that wouldn’t render. Is it the UTF-16? Or the forgotten semicolon? 😡 I’ll stop bothering you, now.