Tag Archives: astronomer

Texas Astronomers Measure Most Massive, Most Unusual Black Hole Using Hobby-Eberly Telescope

By Guest PostNovember 29, 2012Scienceastronomer, austin, bosch, constellation perseus, elliptical, Galaxy, galaxy mass, het data, hobby eberly telescope, karl gebhardt, lenticular galaxy, mass, massive black hole, massive galaxy survey, mcdonald observatory, Milky Way, neptune, ngc 1277, oddball galaxy, pennsylvania state university, remco, sun mass, texas, university, van den

FORT DAVIS, Texas — Astronomers have used the Hobby-Eberly Telescope at The University of Texas at Austin’s McDonald Observatory to measure the mass of what may be the most massive black hole yet — 17 billion times our sun’s mass — in galaxy NGC 1277. The unusual black hole makes up 14 percent of its galaxy’s mass, rather than the usual 0.1 percent. This galaxy and several more in the same study could change theories about how black holes and galaxies form and evolve. The work will appear in the journal Nature on Nov. 29.

NGC 1277 lies 220 million light-years away in the constellation Perseus. The galaxy is only 10 percent the size and mass of our Milky Way. Despite NGC 1277’s diminutive size, the black hole at its heart is more than 11 times as wide as Neptune’s orbit around the sun. (more…)

Astronomers Pin Down Origins of “Mile Markers” for Expansion of Universe

By Guest PostNovember 24, 2012Scienceastronomer, ben shappee, brightness, chemical element, dead stars, kris stanek, lbt, mile markers, mods system, mods1, ohio state university, optical telescope, origin, pattern, pinwheel galaxy, rick pogge, supernova 2011fe, supernovae, type ia, white dwarfs, zombies

COLUMBUS, Ohio – A study using a unique new instrument on the world’s largest optical telescope has revealed the likely origins of especially bright supernovae that astronomers use as easy-to-spot “mile markers” to measure the expansion and acceleration of the universe.

In a paper to appear in the Astrophysical Journal, researchers describe observations of recent supernova 2011fe that they captured with the Large Binocular Telescope (LBT) using a tool created at Ohio State University: the Multi-Object Double Spectrograph (MODS). (more…)

How Galaxies Grow Up

By Guest PostOctober 20, 2012Scienceadam block, age, andromeda galaxy, astronomer, benjamin weiner, blue galaxies, california, computer program, computer simulation, deep2, emission line, galaxies, Galaxy, galaxy evolution, galaxy population, galaxy type, gas, grow up, hawaii, internal motion, keck telescopes, lick observatory, light years, m88 galaxy, massive system, Milky Way, mount lemmon, NASA, observational data, random motion, redshift survey, rotation speed, santa cruz, skycenter, spiral disk shape, star forming galaxies, susan kassin, ua, universe, university, velocity

A study of 544 star-forming galaxies shows that disk galaxies like our own Milky Way reached their current state as orderly rotating pinwheels much later than previously thought, long after much of the universe’s star formation had ceased.

Galaxies are in no hurry to grow up, a team of astronomers has discovered. A comprehensive study of hundreds of galaxies observed by the Keck telescopes in Hawaii and NASA’s Hubble Space Telescope has revealed an unexpected pattern of change that extends back 8 billion years, or more than half the age of the universe.

Researchers say the distant blue galaxies they studied are gradually transforming into rotating disk galaxies like our own Milky Way. Until now, it had not been clear how a galaxy’s organization and internal motion change over time, said Benjamin Weiner, assistant astronomer at the UA Steward Observatory and co-author of the paper describing the findings, which are published in The Astrophysical Journal. (more…)

Bounce, Skid, Wobble: How Huygens Landed on Titan

By Guest PostOctober 11, 2012Science17th century, analysis, astronomer, cassini spacecraft, christiaan huygens, direction, dutch, earth, erich karkoschka, european, evaporate, friction, hazy atmosphere, horizon, huygens data, huygens impact, huygens probe, institute, lower atmosphere, max planck, methane, model, moon, moon surface, motion, mud like, NASA, nicolas altobelli, organic aerosols, ralph lorenz, saturn, space agency, splat, stefan schroder, substance, titan, titan atmosphere, undisturbed terrain

Piecing together the events of the farthest touchdown a manmade spacecraft has ever made on an alien world reveals new clues about Titan’s surface and helps plan future missions to moons and planets.

The Huygens probe, ferried to Saturn’s moon Titan by NASA’s Cassini spacecraft, bounced, slid and wobbled its way to rest in the 10 seconds after touching down on Titan in January 2005, a new analysis reveals. The moon’s surface is more complex than previously thought.

Scientists reconstructed the chain of events by analyzing data from a variety of instruments that were active during the impact, in particular changes in the acceleration experienced by the probe. The probe was supplied by the European Space Agency and named after the Dutch 17th century astronomer Christiaan Huygens. (more…)

First Stars, Galaxies Formed more Rapidly than Expected

By Guest PostSeptember 9, 2012Scienceanalysis, anisotropy probe, Antarctica, astronomer, background, Berkeley, california, christian reichardt, cmb, cosmic microwave, cosmological evolution, data, earth axis, electron, Epoch, Galaxy, geographic, herschel satellite, high resolution, hydrogen atom, image, john carlstrom, kavli foundation, microwave, millimeter wavelength, national, neutral, neutral gas, oliver zahn, period, plasma, polar plateau, proton, radiation, reionization, s chandrasekhar, science foundation, south pole, star, telescope, ultraviolet light, universe, university, wilkinson

Analysis of data from the National Science Foundation’s South Pole Telescope, for the first time, more precisely defines the period of cosmological evolution when the first stars and galaxies formed and gradually illuminated the universe. The data indicate that this period, called the epoch of reionization, was shorter than theorists speculated — and that it ended early.

“We find that the epoch of reionization lasted less than 500 million years and began when the universe was at least 250 million years old,” said Oliver Zahn, a postdoctoral fellow at the Berkeley Center for Cosmological Physics at the University of California, Berkeley, who led the study. “Before this measurement, scientists believed that reionization lasted 750 million years or longer, and had no evidence as to when reionization began.” (more…)

Astronomers Test Einstein in a New Regime Using Pair of Burnt-Out Stars

By Guest PostAugust 31, 2012Sciencealbert einstein, apache point telescope, astronomer, austin, burnt out stars, canary islands, carlos allende prieto, don winget, dwarf stars, einstein, emission, energy, european space agency, fabric, Galaxy, gemini north telescope, general relativity, gran telescopio canarias, gravitational wave, hawaii, j j hermes, j0651, mcdonald observatory, milliseconds, moving object, mukremin kilic, NASA, new mexico, new regime, orbital decay, orbital period, otto struve telescope, ripple, space time, spain, sun, test, texas, theory, university, university of oklahoma, warren brown, west texas

AUSTIN, Texas — A team of astronomers led by researchers from The University of Texas at Austin has confirmed the emission of gravitational waves from the second-strongest known source in our galaxy by studying the shrinking orbital period of a unique pair of burnt-out stars. Their observations tested Albert Einstein’s theory of general relativity in a new regime. The results will be published soon in The Astrophysical Journal Letters.

Last year, the same team discovered that the two white dwarf stars are so close together that they make a complete orbit in less than 13 minutes, and they should be gradually slipping closer. The system, called SDSS J065133.338+284423.37 (J0651 for short), contains two white dwarf stars, which are the remnant cores of stars like our sun. (more…)

Astronomers Using the Hubble Space Telescope Report the Earliest Spiral Galaxy Ever Seen

By Guest PostJuly 19, 2012Sciencealice shapley, astronomer, big bang, bx442, charles steidel, david law, dawn erb, early universe, elliptical galaxy, hawaii, Hubble Space Telescope, james larkin, journal nature, keck observatory, mauna kea volcano, Milky Way, naveen reddy, osiris spectrograph, spiral galaxy, universe

Astronomers have witnessed for the first time a spiral galaxy in the early universe, billions of years before many other spiral galaxies formed. In findings reported July 19 in the journal Nature, the astronomers said they discovered it while using the Hubble Space Telescope to take pictures of about 300 very distant galaxies in the early universe and to study their properties. This distant spiral galaxy is being observed as it existed roughly three billion years after the Big Bang, and light from this part of the universe has been traveling to Earth for about 10.7 billion years.

“As you go back in time to the early universe, galaxies look really strange, clumpy and irregular, not symmetric,” said Alice Shapley, a UCLA associate professor of physics and astronomy, and co-author of the study. “The vast majority of old galaxies look like train wrecks. Our first thought was, why is this one so different, and so beautiful?” (more…)

Astronomers Discover Houdini-Like Vanishing Act in Space

By Guest PostJuly 9, 2012Scienceastronomer, astronomical scale, baffling discovery, benjamin zuckerman, carl melis, Chile, constellation centaurus, dust, dust particles, dusty disc, game changer, gemini observatory, gemini telescope, infrared astronomical satellite, iras, joseph rhee, joy pollard, jupiter, lynette cook, mars, mega flare, mercury, NASA, neptune, norm murray, rocky debris, rocky planet, saturn rings, solar system, tyc 8241 2652, ucla, wise satellite

Astronomers report a baffling discovery never seen before: An extraordinary amount of dust around a nearby star has mysteriously disappeared.

“It’s like the classic magician’s trick — now you see it, now you don’t,” said Carl Melis, a postdoctoral scholar at UC San Diego and lead author of the research. “Only in this case, we’re talking about enough dust to fill an inner solar system, and it really is gone!”

“It’s as if the rings around Saturn had disappeared,” said co-author Benjamin Zuckerman, a UCLA professor of physics and astronomy. “This is even more shocking because the dusty disc of rocky debris was bigger and much more massive than Saturn’s rings. The disc around this star, if it were in our solar system, would have extended from the sun halfway out to Earth, near the orbit of Mercury.” (more…)