Evicted? Possible Black Hole Found 2,600 Light Years from Home

W. M. Keck Observatory press release…

Markarian 177 and SDSS1133
Using the Keck II telescope in Hawaii, researchers obtained high-resolution images of Markarian 177 and SDSS1133 using a near-infrared filter. Credit: W. M. Keck Observatory/M. Koss Et Al.
An international team of researchers analyzing decades of observations from many facilities — including the W. M. Keck Observatory on Mauna Kea, the Pan-STARRS1 telescope on Haleakala and NASA’s Swift satellite — has discovered what appears to be a black hole booted from its host galaxy. The team was led by Michael Koss, who was a postdoctoral fellow at the Institute for Astronomy (IfA) at the University of Hawaii at Manoa during most of the time the study was ongoing. The study will be published in the Nov. 21 edition of Monthly Notices of the Royal Astronomical Society.

The mystery object is part of the dwarf galaxy Markarian 177, located in the bowl of the Big Dipper, a well-known star pattern within the constellation Ursa Major. Although supermassive black holes usually occupy galactic centers, SDSS1133 is located at least 2,600 light-years from its host galaxy’s core. The team was able to detect it in astronomical surveys dating back more than 60 years.

In June 2013, the researchers obtained high-resolution near-infrared images of the object using the 10-meter Keck II telescope at Keck Observatory. “When we analyzed the Keck data, we found the emitting region of SDSS1133 is less than 40 light-years across, and that the center of Markarian 177 shows evidence of intense star formation and other features indicating a recent disturbance that matched what we expected for a recoiling black hole,” said Chao-Ling Hung, a UH Manoa graduate student performing the analysis of the Keck Observatory imaging in the study.

Continue reading “Evicted? Possible Black Hole Found 2,600 Light Years from Home”

The Sky Is Falling

Yes… The sky is falling… Literally.

Anyone who spends a good amount of time observing the night sky is well aware of how common meteors are. On any given night you will see five to ten meteors an hour is you observe carefully from a dark site. This rate goes up dramatically during a meteor shower. Most of the meteors you will see are quite small, ranging from dust grains to smallish sand sized bits. Anything large can be quite spectacular. Something the size of a pebble will create a bright meteor, a bright fireball that streaks across the sky.

Bolide Events from 1994 to 2013
The graphic shows atmospheric impact events from 1994 to 2013, credit NASA’s Near Earth Object (NEO) Program
I have personally witnessed many bright fireballs, it is just a function of how much time you spend outside at night. Meteors that are bright enough to light up the landscape, that leave glowing trains of vapor behind, clouds that last for many minutes, that twist and drift in the high atmospheric winds.

Estimates vary widely, but something like 50,000 tons of meteoric material rains down on the Earth every year. The process that allowed our planet to form continues to this day.

Occasionally a larger object enters the atmosphere. Something big enough to reach the ground intact. Or even something big enough to cause damage from the impact. How often this occurs would be a surprise to most of our fellow citizens who pay little attention to the the natural world around them.

The Chelyabinsk event got the world’s attention. A medium sized object exploded in the atmosphere directly over a mid-sized city causing modest damage. Due to the prevalence of camera gear in modern Russia we were treated to an unprecedented view of this event. With historical events like Tunguska, all we have is eyewitness accounts and a few grainy black and white photographs of the damage taken years after the impact. Now we get dozens of videos of the event that detail how it occurred from dozens of viewpoints.

While this event is unusual, it was not unprecedented, objects of this size will continue to impact our planet. Meanwhile the event fades from public awareness, at least until it happens again… Which it will.

To drive home this point researchers at NASA’s Near Earth Object (NEO) Program have released a map of impacts over the last few years. Using atmospheric sensors that detect the pressure wave of the airburst they were able to locate and estimate the size of the larger events. For further details you can read the press release.

The Chelyabinsk meteor can be seen as a large dot over southern Russia. That event may be the largest dot on the map, but it is not alone. It is the number of other dots that may surprise some people. Our planet is impacted regularly.

Mikaelyan Meteor
A meteor breaking up over Groningen, Netherlands, 18:57, 13 Oct 2009, photo by Robert Mikaelyan, used with permission