The monster in Messier 87 is even more hideous than we had believed.
M87, a giant galaxy in the constellation Virgo, was featured in Nightly News in April 2009. At the time, it was described as harboring a black hole with a mass 2.6 billion times that of the sun. All of a black hole’s mass is compressed into a singularity — a single point. The black hole’s gravity shreds and consumes any star system drifting near, twisting up space-time itself.
On Jan. 12, McDonald Observatory, operated by the University of Texas at Austin, announced that new studies have forced a revision in the monster’s size estimate: not 2.6 billion solar masses, but 6.6 billion times the mass of the sun. McDonald Observatory asserts that this is an “ironclad” figure, derived through observations by the Gemini North Telescope on the crest of Mauna Kea, Hawaii, and the Harlin J. Smith Telescope at McDonald Observatory in western Texas’ Davis Mountains. The instruments are about 309 and 107 inches in diameter, respectively.
“This enormous mass is the largest ever measured for a black hole using a direct technique,” says the observatory’s news release. The revision was possible through timing the rate at which stars circle the black hole as well as measuring “both the central and outermost regions” of M87. Scientists achieved 10 times the resolution previously possible.
M87 is an elliptical galaxy, meaning it is shaped like an egg rather than a pancake; the Milky Way is a spiral galaxy, a pancake. At 120,000 light-years across, M87 is the biggest of the Virgo Cluster of galaxies, which is a collection of more than 2,000 galaxies. M87 is about 54 million light-years away, but it and the others in the Virgo group exert a gravitational pull on our local galaxy group.
Unlike the black hole at our galaxy’s center, the one in M87 is an extremely active beast. As the whirling hole rips stars apart, the shredded material forms a torus of particles around it. McDonald Observatory says this gas is millions of degrees hot. Electromagnetic forces that built up in the swirling material create one of the brightest known radio sources. Astonishingly, the lines of force also eject an enormous, searing jet.
NASA’s Astronomy Picture of the Day for July 6, 2000, describes the jet as a “5,000 light-year long blowtorch where electrons are ejected outward at nearly light-speed, emitting eerily blue light…”
My first attempt at photographing M87, in 2009, failed because of mechanical problems with my telescope. But two years later, on the morning of April 2, working from the same place in Emery County, I managed a series of images that totaled 40 minutes — 20 two-minute subframes, five each with the luminosity, red, green and blue filters.
In my astrophoto, created with normal processing, the galaxy dominates the center of the image, the jet obscured by the bright glow of billions of stars. Two more distant galaxies, which might be mistaken for a jet, are visible in the photo’s 2 o’clock position. Faint dots within M87 and apparently just outside it are some of the globular clusters that orbit it. Each cluster can contain hundreds of thousands of stars; M87 has captured an estimated 15,000 globulars.
[My view of M87, taken the morning of April 2, 2011, shown with normal processing. For a larger version, click HERE]
When the photo is processed to cut the galaxy’s glare — and reduce the brightness of everything else — the bright nucleus is visible as well as the jet blasting from the black hole. The flare at the edge of the image at the 9 o’clock position is an overexposed star in our own galaxy]
[When the view is processed to reduce brightness, the nucleus and jet are visible. The jet is around the 11 o’clock position. For a larger version, click HERE]
Enlarge that image and the nucleus and the scorching blue jet blaze forth.
[The central part of the same image, enlarged to better show M87’s nucleus and the black hole’s jet. For a larger version, click HERE]