A frosty, chilly star about the same temperature as the North Pole, minus 54 and 9 degrees Fahrenheit (minus 48 to minus 13 degrees Celsius)
Space news (astrophysics: faint, cool stars; brown dwarfs) – the fourth closest detected star system to Earth, just 7.2 light-years toward the constellation Hydra –
A young, ambitious astronomer working at Pennsylvania State University’s Center for Exoplanets and Habitable Worlds discovered the dimmest, coolest brown dwarf detected during the human journey to the beginning of space and time. Kevin Lehman first noticed a fast moving object, quickly dubbed WISE J085510.83-071442.5, in March of 2013. Excited at a new discovery, he spent the next few days analyzing more images of the same part of the sky taken by NASA’s Spitzer Space Telescope and Gemini South Telescope on Cerro Pachon in Chile.
“It’s very exciting to discover a new neighbor of our solar system that is so close,” said Kevin Luhman, an astronomer at Pennsylvania State University’s Center for Exoplanets and Habitable Worlds, University Park. “And given its extreme temperature, it should tell us a lot about the atmospheres of planets, which often have similarly cold temperatures.”
Kevin Luhman originally spotted the fast motion of WISE J085510.83-071442.5 in infrared images taken by NASA’s Wide-field Infrared Survey Explorer (WISE). Later analysis of infrared images taken by NASA’s Spitzer Space Telescope were needed to determine its chilly temperature of between minus (54-9) Fahrenheit [minus (13 – 48) degrees Celsius]. Astronomers would use measurements taken by Spitzer and WISE at different positions around the sun to determine its distance of 7.2 light-years from Earth using the parallax effect. To scientists, it added up to a brown dwarf or maybe a large Jupiter-size planet lost in space.
“This object appeared to move really fast in the WISE data,” said Luhman. “That told us it was something special.”
Additional calculations estimated the mass of WISE J085510.83-071442.5 at between 3 and 10 times the mass of Jupiter. It could be a gas giant like Jupiter that was flung out of its host star system by gravitational interactions with more massive bodies. Astronomers determined it was more likely a very cool brown dwarf than a large gas giant planet since they have been detected more often. If this is the case, it’s the coldest brown dwarf star discovered during the human journey to the beginning of space and time. A nice shiny feather in the hat of a young, aspiring astronomer on the rise.
“It is remarkable that even after many decades of studying the sky, we still do not have a complete inventory of the sun’s nearest neighbors,” said Michael Werner, the project scientist for Spitzer at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. JPL manages and operates Spitzer. “This exciting new result demonstrates the power of exploring the universe using new tools, such as the infrared eyes of WISE and Spitzer.”
Work’s never done
Never one to rest on his laurels, in March of 2013, Kevin Luhman discovered a pair of warmer brown dwarf stars just 6.5 light-years from Earth during his analysis of WISE images. Since this time, his search for rapidly moving bodies close to Earth has also shown that the outer solar system probably doesn’t contain a large, undiscovered planet X or Nemesis, as people often refer to it. I did mention he was ambitious.
The seed out of which some of these mysterious, lurking monsters were born
Space news (astrophysics: black hole formation: early black holes) – supermassive black holes scattered around the observable universe –
Astronomers believe and data suggests at the center of nearly all large galaxies, including the Milky Way, lurks a supermassive black hole with millions and even billions of times the mass of our sun. Gigantic black holes that in some cases formed less than a billion years after the birth of the cosmos. For the first time, they have uncovered evidence suggesting some of these early supermassive black holes formed directly during the collapse of a giant gas cloud. A finding making astronomers rethink current theories on the formation of these enigmatic, invisible monsters.
“Our discovery, if confirmed, explains how these monster black holes were born,” said Fabio Pacucci of Scuola Normale Superiore (SNS) in Pisa, Italy, who led the study. “We found evidence that supermassive black hole seeds can form directly from the collapse of a giant gas cloud, skipping any intermediate steps.”
Intermediate steps like the formation of a supermassive star and its subsequent destruction during a supernova. Evidence to date suggests black holes are formed during this process and then supermassive black holes are produced by mergers between black holes. But this new finding suggests things get a little weirder than first thought. Maybe things are weirder than we could ever imagine. It could be the first supermassive black holes seeds were intermediate mass black holes, monsters in the 20,000 solar mass range. Watch this YouTube video on black hole formation.
Imagine the volume of a gas cloud capable of contracting directly into an object tens times, or more, the mass of Sol. Black hole seeds built up by drawing in cold gas and dust appear to have formed within the first billion years of the cosmos. Maybe once they confirm the existence of the two black hole seeds they think they detected. They can try to get some data on the mass of these early black hole seeds. At the moment, no mass data is available. Watch this YouTube video on black hole seeds.
The forming of a supermassive black hole directly from the collapse of a massive cloud of gas seems even weirder than the observed formation process for supermassive black holes. But we’re not in Kansas anymore, so anything could theoretically be possible. I am certain, things are even weirder than we can imagine.
“There is a lot of controversy over which path these black holes take,” said co-author Andrea Ferrara, also of SNS. “Our work suggests we are narrowing in on an answer, where the black holes start big and grow at the normal rate, rather than starting small and growing at a very fast rate.”
The team used computer models of the formation of black hole seeds combined with new techniques and methods to identify two possible candidates for early supermassive black holes in long-exposure Hubble, Chandra, and Spitzer images. The data collected on these two candidates matches the theoretical profile expected and estimates of their age suggest they formed when the cosmos was less than a billion years old. But more study is needed to verify the data and existence of these theoretical early black hole seeds.
“Black hole seeds are extremely hard to find and confirming their detection is very difficult,” said Andrea Grazian, a co-author from the National Institute for Astrophysics in Italy. “However, we think our research has uncovered the two best candidates to date.”
The team plans additional observations to see if these two candidates have other properties of black hole seeds as computer simulations predict. Real evidence to prove or disprove their early supermassive black hole formation theory might have to wait for a few years. Until the James Webb Space Telescope, European Extremely Large Telescope and other assets come online. The team and other astronomers are currently designing the theoretical framework needed to interpret future data and pinpoint the existence of some of the first supermassive black holes ever to exist. Watch this YouTube video on the jet of Centaurus A.
Read the scientific paper released on the first identification of black hole seeds here.