Featured series 
Tag: Cosmology
-
Science & Tech
Frequent starbursts sterilize center of Milky Way
A scenario in which exploding stars kill all life within the center of our galaxy is detailed by stronomer Antony Stark (Harvard-Smithsonian Center for Astrophysics) and colleagues in the October 10, 2004, issue of The Astrophysical Journal Letters. The team’s discovery was made possible using the unique capabilities of the Antarctic Submillimeter Telescope and Remote…
-
Science & Tech
Galactic collision reveals fate of Milky Way galaxy
Sixty-eight million light-years away, the Antennae galaxies are locked in a dance of death, with stars being ripped from their orbits and spiral arms being shredded into streamers that dangle in space. Several billion years from now, our home — the Milky Way galaxy — might look the same as the Andromeda galaxy smashes into…
-
Science & Tech
Some globular clusters may be leftovers from snacking galaxies
According to the hierarchical theory of galaxy formation, galaxies have grown larger over time by consuming smaller dwarf galaxies and star clusters. And sometimes, it seems that the unfortunate prey is not swallowed whole but instead is munched like a peach, stripped of its outer layers to leave behind only the pit. New findings by…
-
Science & Tech
Raging storms of hot and cold gas
New observations with the Space Telescope Imaging Spectrograph (STIS), Hubble’s high-precision and ultra-sensitive spectrometer, show that the warm chromosphere of Betelgeuse extends out to more than 50 times its radius in visible light, a size five times larger than the orbit of Neptune. (The chromosphere is an inner layer of a star’s atmosphere, between the…
-
Science & Tech
Suns of all ages possess comets, maybe planets
Astronomers observed a comet puffing out huge amounts of carbon, one of the key elements for life. The comet also emitted large amounts of water vapor as the Sun’s heat baked its outer surface. When combined with previous observations suggesting the presence of evaporating comets near young stars like Beta Pictoris and old stars like…
-
Science & Tech
Planetary survivor strategy: Outeat, outweigh, outlast!
Astronomers Myron Lecar and Dimitar Sasselov have found that planet formation is a contest, where a growing planet must fight for survival lest it be swallowed by the star that initially nurtured it. Of the first 100 stars found to harbor planets, more than 30 stars host a Jupiter-sized world in an orbit smaller than…
-
Campus & Community
Picturing a universe that’s out of sight
Giovanni Fazio, a senior physicist at the Harvard-Smithsonian Center for Astrophysics, directed the design and construction of a camera that is looking beyond the visible universe to see planets, stars, and galaxies being born. On Aug. 25, 2003, he waited for the ignition of a Delta rocket, with extra boosters strapped to it, to blast…
-
Science & Tech
First supernovae quickly seeded universe with stuff of life
The early universe was a barren wasteland of hydrogen, helium, and a touch of lithium, containing none of the elements necessary for life as we know it. From those primordial gases were born giant stars 200 times as massive as the Sun, burning their fuel at such a prodigious rate that they lived for only…
-
Science & Tech
Harvard continues legacy of Cepheid discoveries
Cepheids are important to astronomers for their key role as extragalactic distance indicators. Cepheids are variable stars that regularly brighten and dim as they pulsate rhythmically. Their pulsation period is proportional to their intrinsic brightness – the longer the period, the brighter the star. A comparison of intrinsic to apparent brightness yields the distance to…
-
Science & Tech
Do we live in a “stop and go” universe?
At the 202nd meeting of the American Astronomical Society, Robert Kirshner (Harvard-Smithsonian Center for Astrophysics), on behalf of the international High-z Supernova Search Team led by Brian Schmidt (Mount Stromlo Observatory), presented evidence that the expanding universe slowed for billions of years before galaxies began accelerating, like cars that get past a bottleneck. “Right now,…
-
Science & Tech
Molecular cloud has a heartbeat
Barnard 68, located 300 light-years away in the constellation Ophiuchus, is a typical example of small, dark molecular clouds known as Bok Globules. Such dense, cold clouds of dust and gas appear black in photos because the dust blocks visible light from background stars. Molecular clouds are stellar nurseries. Young stars form from collapsing molecular…
-
Science & Tech
First Milky Ways found at edge of universe
One key question that has puzzled astronomers for decades is: When did the first stars and galaxies form after the Big Bang occurred? The answer — very quickly! Astronomers Rennan Barkana of Tel Aviv University and Avi Loeb of the Harvard-Smithsonian Center for Astrophysics found the first direct evidence that galaxies as large as the…
-
Science & Tech
Hypergiant star erupts
In the year 2000, the star Rho Cassiopeiae, n the constellation of Cassiopeia, lost more mass than in any other stellar eruption observed by astronomers. An international team of astronomers, led by astrophysicist Alex Lobel of the Harvard-Smithsonian Center for Astrophysics, observed the huge eruption, which blasted nearly 10,000 times the mass of the Earth…
-
Science & Tech
Scientists look inside antimatter
“We have obtained the first glimpse inside an antihydrogen atom, and this is a significant step on the way to precision measurements that will allow matter/antimatter comparisons to be made,” says Gerald Gabrielse, professor of physics at Harvard and leader of the research team. Such comparisons could show why antimatter and matter have not destroyed…
-
Science & Tech
From cradle to grave
Astronomers have been using the Chandra X-ray Observatory and radio telescopes to observe two opposing jets of high-energy particles emitted following an outburst, first detected in 1998 by NASA’s Rossi X-ray Timing Explorer, from the double-star system XTE J1550-564. The X-ray jets, which require a continuous source of trillion-volt electrons to remain bright, were observed…
-
Science & Tech
X-ray arcs tell tale of giant eruption
Scientists from the Harvard-Smithsonian Center for Astrophysics (CfA) report that two arc-like structures of multimillion-degree gas in the galaxy Centaurus A appear to be part of a ring 25,000 light years in diameter. The size and location of the ring suggest that it could have been produced in a titanic explosion that occurred about 10…
-
Science & Tech
Neither Rome nor universe built in a day
Theoretical astrophysicists Stuart B. Wyithe and Abraham Loeb at the Harvard-Smithsonian Center for Astrophysics (CfA) have explained a paradox that has troubled scientists for years. Observations seem to show that giant black holes containing as much mass as three billion suns formed less than a billion years after the Big Bang. Collecting so much material…
-
Science & Tech
Culprit caught in gamma-ray burst mystery
Gamma-ray bursts have long puzzled astronomers. “The hunt for the source of gamma-ray bursts has been a detective story as challenging as any faced by the famous Lieutenant Columbo. We were thrilled to be the first to catch a supernova ‘in the act,’ so to speak,” says Kris Stanek of the Harvard-Smithsonian Center for Astrophysics.…
-
Science & Tech
When worlds collide
Astronomers believe the a mega-merger in the galaxy known as Arp 220 triggered the formation of huge numbers of new stars, sent shock waves rumbling through intergalactic space, and could possibly lead to the formation of a supermassive black hole in the center of the new conglomerate galaxy. Data collected by the Chandra X-ray observatory…
-
Science & Tech
Even stars use sunscreen!
Mira variable stars are named after the red giant star Mira (omicron Ceti) in the constellation Cetus the Whale. Variable stars brighten, then dim, then brighten again. While astronomers have known of the existence of these dramatically changing stars for hundreds of years, the cause of their variability has been hard to identify. Now, two…
-
Science & Tech
Looking toward the end
Among astronomers there is almost a consensus that universal expansion will go on forever, with galaxies and clusters of galaxies moving away from each other so fast that gravity cannot ever pull them together. Since 1998, astronomers have found good evidence that this expansion is accelerating, that galaxies are separating at ever-increasing speed. But what…
-
Science & Tech
Atmosphere detected on distant world orbiting another star
One-hundred-and-fifty light years away from Earth, in the constellation Pegasus, is a star known as HD 209458. Using NASA’s Hubble Space Telescope, a research team was able to detect the atmosphere of a planet orbiting the star. This marks the first time that scientists were able to observe the atmosphere of a planet outside our…
-
Science & Tech
Astronomers take the measure of dark matter in the universe
Astronomers believe that most of the matter in the universe is invisible to us — so called “dark matter.” The nature of this dark matter is not known, but most astronomers think that it is in the form of an as-yet-unknown type of elementary particle that contributes to gravity through its mass but otherwise interacts…
-
Science & Tech
Young stars in Orion may solve mystery of our solar system
Scientists who study how our solar system formed have been hard pressed to explain the presence of extremely unusual chemical isotopes found in ancient meteoroids orbiting the Earth. The isotopes are short-lived and had to have been formed no earlier than the creation of the solar system, some five billion years ago. Yet these elements…
-
Science & Tech
Young pulsar reveals clues to supernova
Using the Chandra X-ray Observatory to learn more about pulsars, A team led by Stephen Murray of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., studied 3C58, the remains of a supernova observed on Earth in 1181 AD in the constellation Cassiopeia. 3C58 is one of the youngest known pulsars, and behaves quite differently from…
-
Science & Tech
Astronomers detect dust disks around very young brown dwarfs in the Orion Nebula
The results of recent observations by an international team of astronomers suggest that brown dwarfs share a common origin with stars. Brown dwarfs are more similar in nature to stars than to planets and, like stars, have the potential to form with accompanying systems of planets. The observation by the researchers of dusty protoplanetary disks…
-
Science & Tech
Star factory near galactic center bathed in high-energy X-rays
A team of astronomers, including some from the Harvard-Smithsonian Center for Astrophysics, has looked into the core of our own Milky Way galaxy and discovered a new phenomenon. The “cauldron” of 60-million-degree gas surrounding a group of young stars in the Arches Cluster supports earlier theoretical predictions about what happens when solar winds from massive…
-
Science & Tech
A quasar’s identity may simply be in eye of beholder
A quasar is a super-massive black hole; quasars are among the most energetic objects in the Universe. Most quasars are extremely bright in optical light, but about 10 percent of them appear hidden by clouds of gas and dust. Are these 10 percent different from the rest of the quasars? Astronomers have debated whether these…
-
Science & Tech
Young star may be belching spheres of gas, astronomers say
Observations by astronomers of a young star in the constellation Cepheus, more than 2000 lights-years away, suggest that it is repeatedly belching spheres of gas. Current theories about how young stars shed matter would not have predicted such eruptions. In order to remain stable while accumulating matter, young stars have to throw off some of…
-
Science & Tech
Gamma-ray astronomers detect “extreme” galaxies
Gamma rays from X-ray emitting galaxies seem to signal the existence of what astronomers are calling “extreme” galaxies. An international team of astrophysicists made the discovery of very-high-energy gamma rays, confirming the hypothesis of an Italian group that galaxies which emit strongly in the highest energy X-rays would also emit the most energetic gamma rays.…