Deep Survey Looks for Faint Objects in Nearby Stellar Nursery
Using NASA's Hubble Space Telescope to peer deep into the vast stellar nursery called the Orion Nebula, astronomers searched for small, faint bodies. What they found was the largest population yet of brown dwarfs — objects that are more massive than planets but do not shine like stars. Researchers identified 17 brown dwarf companions to red dwarf stars, one brown dwarf pair, and one brown dwarf with a planetary companion. They also found three giant planets, including a binary system where two planets orbit each other in the absence of a parent star. This survey could only be done with Hubble’s exceptional resolution and infrared sensitivity.
NASA Great Observatories Team-up to Identify Flickering Black Hole
Supermassive black holes, weighing millions of times as much as our Sun, are gatherers not hunters. Embedded in the hearts of galaxies, they will lie dormant for a long time until the next meal happens to come along.
The team of astronomers using observations from the Hubble Space Telescope, the Chandra X-ray Observatory, and as well as the W.M. Keck Observatory in Mauna Kea, Hawaii, and the Apache Point Observatory (APO) near Sunspot, New Mexico, zeroed in on a flickering black hole.
A black hole in the center of galaxy SDSS J1354+1327, located about 800 million light-years away, appears to have consumed large amounts of gas while blasting off an outflow of high-energy particles. The fresh burst of fuel might have been supplied by a bypassing galaxy. The outflow eventually switched off then turned back on about 100,000 years later. This is strong evidence that accreting black holes can switch their power output off and on again over timescales that are short compared to the 13.8-billion-year age of the universe.
Small, Embryonic Galaxy Formed Just 500 Million Years After the Big Bang
As powerful as NASA’s Hubble and Spitzer space telescopes are, they need a little help from nature in seeking out the farthest, and hence earliest galaxies that first appeared in the universe after the big bang. This help comes from a natural zoom lens in the universe, formed by the warping of space by intense gravitational fields.
The most powerful “zoom lenses” out there are formed by very massive foreground clusters that bend space like a bowling ball rolling across a soft mattress. The lens boosts the brightness of distant background objects. The farthest candidates simply appear as red dots in Hubble photos because of their small size and great distance.
However, astronomers got very lucky when they looked at galaxy cluster SPT-CL J0615-5746. Embedded in the photo is an arc-like structure that is not only the amplified image of a background galaxy, but an image that has been smeared into a crescent-shape. This image allowed astronomers to estimate that the diminutive galaxy weighs in at no more than 3 billion solar masses (roughly 1/100th the mass of our fully grown Milky Way galaxy). It is less than 2,500 light-years across, half the size of the Small Magellanic Cloud, a satellite galaxy of our Milky Way. The object is considered prototypical of young galaxies that emerged during the epoch shortly after the big bang. Hubble’s clarity, combined with Spitzer’s infrared sensitivity to light reddened by the expanding universe, allowed for the object’s vast distance to be calculated.
Swarms of Young and Older Stars Yield Clues to our Galaxy’s Formation
Every star has a story to tell. Study a star and it will give you information about its composition, age, and possibly even clues to where it first formed. The stars residing in the oldest structure of our Milky Way galaxy, the central bulge, offer insight into how our pinwheel-shaped island of myriad stars evolved over billions of years. Think of our Milky Way as a pancake-shaped structure with a big round dollop of butter in the middle — that would be our galaxy’s central hub.
For many years, astronomers had a simple view of our Milky Way’s bulge as a quiescent place composed of old stars, the earliest homesteaders of our galaxy. A new analysis of about 10,000 normal Sun-like stars in the bulge reveals that our galaxy’s hub is a dynamic environment of variously aged stars zipping around at different speeds, like travelers bustling about a busy airport. This conclusion is based on nine years’ worth of archival data from the Hubble Space Telescope. The faster-moving and later-generation stars may have arrived at the hub through our Milky Way cannibalizing smaller galaxies. They mingle with a different population of older, slowing-moving stars. Currently, only Hubble has sharp enough resolution to simultaneously measure the motions of thousands of Sun-like stars at the bulge's distance from Earth.
Unprecedented Fly-through Combines the Visible and Infrared Vision of the Hubble and Spitzer Space Telescopes
By combining the visible and infrared capabilities of the Hubble and Spitzer space telescopes, astronomers and visualization specialists from NASA's Universe of Learning program have created a spectacular, three-dimensional, fly-through movie of the magnificent Orion nebula, a nearby stellar nursery. Using actual scientific data along with Hollywood techniques, a team at the Space Telescope Science Institute in Baltimore, Maryland, and the Caltech/IPAC in Pasadena, California, has produced the best and most detailed multi-wavelength visualization yet of the Orion nebula. The three-minute movie allows viewers to glide through the picturesque star-forming region and experience the universe in an exciting new way.