Astronomy
Two Bizarre Brown Dwarfs Found With Citizen Scientists’ Help
This artist’s concept shows a brown dwarf, a ball of gas not massive enough to power itself the way stars do. Despite their name, brown dwarfs would appear magenta or orange-red to the human eye if seen close up. Credit: CC byWilliam Pendrill
With the help of citizen scientists, astronomers have discovered two highly unusual brown dwarfs, balls of gas that are not massive enough to power themselves the way stars do.
Participants in the NASA-funded Backyard Worlds: Planet 9 project helped lead scientists to these bizarre objects, using data from NASA’s Near-Earth Object Wide-Field Infrared Survey Explorer (NEOWISE) satellite along with all-sky observations collected between 2009 and 2011 under its previous moniker, WISE. Backyard Worlds: Planet 9 is an example of “citizen science,” a collaboration between professional scientists and members of the public.
Scientists call the newly discovered objects “the first extreme T-type subdwarfs.” They weigh about 75 times the mass of Jupiter and clock in at roughly 10 billion years old. These two objects are the most planetlike brown dwarfs yet seen among the Milky Way’s oldest population of stars.
What’s Up – October 2019
Published by NASA
Link to article with video: https://www.jpl.nasa.gov/video/details.php?id=1588
Link to page: International Observe the Moon Night, Oct 5, 2019
What can you see in the October sky? Join the global celebration of International Observe the Moon Night on Oct. 5th, then try to catch the ice giant planets Uranus and Neptune, which are well placed for viewing in the late night sky.
Transcript:
What’s Up for October? A night for the whole world to observe the Moon and hunting for ice giants!
International Observe the Moon Night is Oct. 5th. It’s an annual celebration of lunar observation and exploration. Events are scheduled in lots of places around the world, so there may be one near you. But all you really need to participate is to go out and look up.
The event is timed to coincide with the first quarter moon. This allows for some great observing along the lunar terminator – the line that divides the dayside from the nightside. With even a small pair of binoculars, you can see some great details as features like mountains and craters pop up into the light. Learn more and look for events in your area at moon.nasa.gov/observe.
October is a great time to try and capture an ICE GIANT. Now, these aren’t mythical creatures. They’re planets – the most distant of the major planets of our solar system, Uranus and Neptune.
The four giant planets of our solar system are not created equal. The gas giants, Jupiter and Saturn, are much bigger and way more massive, while the ice giants are so named because they contain a much higher amount of materials that typically form ices in the frigid depths of the outer solar system.
In October, both Uranus and Neptune are well placed in the late night sky. In fact, you can see all four giant planets in the same evening if you look for Jupiter and Saturn in the west after sunset, and then come back a couple of hours later to spot Uranus and Neptune. (Think of it as your own personal “Voyager mission.” NASA’s Voyager 2 is the only spacecraft to have visited the ice giants so far, although scientists are eager to go back for a more detailed study.)
Unlike Jupiter and Saturn, the ice giants are quite faint, so the best way to observe them is with a telescope, and from personal experience, it’s much easier to find them if you have a computer-controlled mount that can automatically point the telescope for you. If you don’t have access to one, find a local event with the Night Sky Network at nightsky.jpl.nasa.gov. Otherwise, sky watching apps can help you star-hop your way to these two incredibly distant planets.
Now be advised, because they’re so far away, each planet appears as just a point of light. But with a modest telescope, you’ll see Uranus as a tiny disk. You’d be forgiven for mistaking Neptune as a star – it’s the same size as Uranus, but much farther away, so it’s fainter.
The ice giants are elusive, but well worth the effort to say you’ve seen them with your own eyes.
Here are the phases of the Moon for October. You can catch up on all of NASA’s current and future missions at nasa.gov. I’m Preston Dyches from NASA’s Jet Propulsion Laboratory, and that’s What’s Up for this month.
Ancient Stardust Sheds Light on the First Stars
This research was presented in a paper entitled “Dust in the Reionization Era: ALMA Observations of a z =8.38 Gravitationally-Lensed Galaxy”
by Laporte et al., to appear in The Astrophysical Journal Letters.
An international team of astronomers, led by Nicolas Laporte of University College London, have used the Atacama Large Millimeter/submillimeter Array (ALMA) to observe A2744_YD4, the youngest and most remote galaxy ever seen by ALMA. They were surprised to find that this youthful galaxy contained an abundance of interstellar dust — dust formed by the deaths of an earlier generation of stars.
Follow-up observations using the X-shooter instrument on ESO’s Very Large Telescope confirmed the enormous distance to A2744_YD4. The galaxy appears to us as it was when the Universe was only 600 million years old, during the period when the first stars and galaxies were forming [1].
‘Heartbeat Stars’ Unlocked in New Study
Written by Elizabeth Landau
Jet Propulsion Laboratory, Pasadena, Calif.
October 21, 2016
This artist’s concept depicts ”heartbeat stars,” which have been detected by NASA’s Kepler Space Telescope and others. Image credit: NASA/JPL-Caltech
Matters of the heart can be puzzling and mysterious – so too with unusual astronomical objects called heartbeat stars.
Heartbeat stars, discovered in large numbers by NASA’s Kepler space telescope, are binary stars (systems of two stars orbiting each other) that got their name because if you were to map out their brightness over time, the result would look like an electrocardiogram, a graph of the electrical activity of the heart. Scientists are interested in them because they are binary systems in elongated elliptical orbits. This makes them natural laboratories for studying the gravitational effects of stars on each other.
In a heartbeat star system, the distance between the two stars varies drastically as they orbit each other. Heartbeat stars can get as close as a few stellar radii to each other, and as far as 10 times that distance during the course of one orbit.
Read the rest of this entry »
NASA, Citizen Scientists Discover Potential New Hunting Ground for Exoplanets
Via a NASA-led citizen science project, eight people with no formal training in astrophysics helped discover what could be a fruitful new place to search for planets outside our solar system – a large disk of gas and dust encircling a star known as a circumstellar disk.
A paper, published in The Astrophysical Journal Letters and coauthored by eight citizen scientists involved in the discovery, describes a newly identified red dwarf star, AWI0005x3s, and its warm circumstellar disk, the kind associated with young planetary systems. Most of the exoplanets, which are planets outside our solar system, that have been imaged to date dwell in disks similar to the one around AWI0005x3s.
The disk and its star are located in what is dubbed the Carina association – a large, loose grouping of similar stars in the Carina Nebula approximately 212 light years from our sun. Its relative proximity to Earth will make it easier to conduct follow-on studies.
NASA’s Juno to Soar Closest to Jupiter This Saturday
This Saturday at 5:51 a.m. PDT, (8:51 a.m. EDT, 12:51 UTC) NASA’s Juno spacecraft will get closer to the cloud tops of Jupiter than at any other time during its prime mission. At the moment of closest approach, Juno will be about 2,600 miles (4,200 kilometers) above Jupiter’s swirling clouds and traveling at 130,000 mph (208,000 kilometers per hour) with respect to the planet. There are 35 more close flybys of Jupiter scheduled during its prime mission (scheduled to end in February of 2018). The Aug. 27 flyby will be the first time Juno will have its entire suite of science instruments activated and looking at the giant planet as the spacecraft zooms past.
“This is the first time we will be close to Jupiter since we entered orbit on July 4,” said Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio. “Back then we turned all our instruments off to focus on the rocket burn to get Juno into orbit around Jupiter. Since then, we have checked Juno from stem to stern and back again. We still have more testing to do, but we are confident that everything is working great, so for this upcoming flyby Juno’s eyes and ears, our science instruments, will all be open.”
“This is our first opportunity to really take a close-up look at the king of our solar system and begin to figure out how he works,” Bolton said.
While the science data from the pass should be downlinked to Earth within days, interpretation and first results are not expected for some time.
“No other spacecraft has ever orbited Jupiter this closely, or over the poles in this fashion,” said Steve Levin, Juno project scientist from NASA’s Jet Propulsion Laboratory in Pasadena, California. “This is our first opportunity and there are bound to be surprises. We need to take our time to make sure our conclusions are correct.”
Not only will Juno’s suite of eight science instruments be on, the spacecraft’s visible light imager — JunoCam will also be snapping some closeups. A handful of JunoCam images, including the highest resolution imagery of the Jovian atmosphere and the first glimpse of Jupiter’s north and south poles, are expected to be released during the later part of next week.
The Juno spacecraft launched on Aug. 5, 2011, from Cape Canaveral, Florida. JPL manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. Juno is part of NASA’s New Frontiers Program, which is managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for NASA’s Science Mission Directorate. Lockheed Martin Space Systems, Denver, built the spacecraft. Caltech, in Pasadena, California, manages JPL for NASA.
More information on the Juno mission is available at: http://www.nasa.gov/juno
Follow the mission on Facebook and Twitter at: http://www.facebook.com/NASAJuno or http://www.twitter.com/NASAJuno
Gluttonous Star May Hold Clues to Planet Formation
In 1936, the young star FU Orionis began gobbling material from its surrounding disk of gas and dust with a sudden voraciousness. During a three-month binge, as matter turned into energy, the star became 100 times brighter, heating the disk around it to temperatures of up to 12,000 degrees Fahrenheit (7,000 Kelvin). FU Orionis is still devouring gas to this day, although not as quickly.
This brightening is the most extreme event of its kind that has been confirmed around a star the size of the sun, and may have implications for how stars and planets form. The intense baking of the star’s surrounding disk likely changed its chemistry, permanently altering material that could one day turn into planets.
“By studying FU Orionis, we’re seeing the absolute baby years of a solar system,” said Joel Green, a project scientist at the Space Telescope Science Institute, Baltimore, Maryland. “Our own sun may have gone through a similar brightening, which would have been a crucial step in the formation of Earth and other planets in our solar system.”
Visible light observations of FU Orionis, which is about 1,500 light-years away from Earth in the constellation Orion, have shown astronomers that the star’s extreme brightness began slowly fading after its initial 1936 burst. But Green and colleagues wanted to know more about the relationship between the star and surrounding disk. Is the star still gorging on it? Is its composition changing? When will the star’s brightness return to pre-outburst levels?
To answer these questions, scientists needed to observe the star’s brightness at infrared wavelengths, which are longer than the human eye can see and provide temperature measurements.
Green and his team compared infrared data obtained in 2016 using the Stratospheric Observatory for Infrared Astronomy, SOFIA, to observations made with NASA’s Spitzer Space Telescope in 2004. SOFIA, the world’s largest airborne observatory, is jointly operated by NASA and the German Aerospace Center and provides observations at wavelengths no longer attainable by Spitzer. The SOFIA data were taken using the FORCAST instrument (Faint Object infrared Camera for the SOFIA Telescope).
“By combining data from the two telescopes collected over a 12-year interval, we were able to gain a unique perspective on the star’s behavior over time,” Green said. He presented the results at the American Astronomical Society meeting in San Diego, this week.
Using these infrared observations and other historical data, researchers found that FU Orionis had continued its ravenous snacking after the initial brightening event: The star has eaten the equivalent of 18 Jupiters in the last 80 years.
The recent measurements provided by SOFIA inform researchers that the total amount of visible and infrared light energy coming out of the FU Orionis system decreased by about 13 percent over the 12 years since the Spitzer observations. Researchers determined that this decrease is caused by dimming of the star at short infrared wavelengths, but not at longer wavelengths. That means up to 13 percent of the hottest material of the disk has disappeared, while colder material has stayed intact.
“A decrease in the hottest gas means that the star is eating the innermost part of the disk, but the rest of the disk has essentially not changed in the last 12 years,” Green said. “This result is consistent with computer models, but for the first time we are able to confirm the theory with observations.”
Astronomers predict, partly based on the new results, that FU Orionis will run out of hot material to nosh on within the next few hundred years. At that point, the star will return to the state it was in before the dramatic 1936 brightening event. Scientists are unsure what the star was like before or what set off the feeding frenzy.
“The material falling into the star is like water from a hose that’s slowly being pinched off,” Green said. “Eventually the water will stop.”
If our sun had a brightening event like FU Orionis did in 1936, this could explain why certain elements are more abundant on Mars than on Earth. A sudden 100-fold brightening would have altered the chemical composition of material close to the star, but not as much farther from it. Because Mars formed farther from the sun, its component material would not have been heated up as much as Earth’s was.
At a few hundred thousand years old, FU Orionis is a toddler in the typical lifespan of a star. The 80 years of brightening and fading since 1936 represent only a tiny fraction of the star’s life so far, but these changes happened to occur at a time when astronomers could observe.
“It’s amazing that an entire protoplanetary disk can change on such a short timescale, within a human lifetime,” said Luisa Rebull, study co-author and research scientist at the Infrared Processing and Analysis Center (IPAC), based at Caltech, Pasadena, California.
Green plans to gain more insight into the FU Orionis feeding phenomenon with NASA’s James Webb Space Telescope, which will launch in 2018. SOFIA has mid-infrared high-resolution spectrometers and far-infrared science instrumentation that complement Webb’s planned near- and mid-infrared capabilities. Spitzer is expected to continue exploring the universe in infrared light, and enabling groundbreaking scientific investigations, into early 2019.
NASA’s Jet Propulsion Laboratory, Pasadena, California, manages the Spitzer Space Telescope mission for NASA. Science operations are conducted at the Spitzer Science Center at Caltech. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech. Caltech manages JPL for NASA.
SOFIA is a joint project of NASA and the German Aerospace Center (DLR). The aircraft is based at NASA Armstrong Flight Research Center’s facility in Palmdale, California. NASA’s Ames Research Center in Moffett Field, California, manages the SOFIA science and mission operations in cooperation with the Universities Space Research Association (USRA) headquartered in Columbia, Maryland, and the German SOFIA Institute (DSI) at the University of Stuttgart.
For more information about Spitzer, visit: http://www.nasa.gov/ or http://spitzer.caltech.edu
For more information about SOFIA, visit: http://www.nasa.gov/sofia or http://www.dlr.de/en/sofia
NASA Extends Hubble Space Telescope Science Operations Contract
This action will extend the period of performance from July 1 through June 30, 2021. The contract value will increase by approximately $196.3 million for a total contract value of $2.03 billion.
This contract extension covers the work necessary to continue the science program of the Hubble mission by the Space Telescope Science Institute. The support includes the products and services required to execute science system engineering, science ground system development, science operations, science research, grants management and public outreach support for Hubble and data archive support for missions in the Mikulski Archive for Space Telescopes.
After the final space shuttle servicing mission to the telescope in 2009, Hubble is better than ever. Hubble is expected to continue to provide valuable data into the 2020’s, securing its place in history as an outstanding general purpose observatory in areas ranging from our solar system to the distant universe.
In 2018, NASA’s James Webb Space Telescope will be launched into space as the premier observatory of the next decade, serving astronomers worldwide to build on Hubble’s legacy of discoveries and help unlock some of the biggest mysteries of the universe.
For information about NASA and agency programs, visit: http://www.nasa.gov
Clues About How Giant Black Holes Formed So Quickly
Using data from NASA’s Great Observatories, astronomers have found the best evidence yet for cosmic seeds in the early universe that should grow into supermassive black holes.
Researchers combined data from NASA’s Chandra X-ray Observatory, Hubble Space Telescope, and Spitzer Space Telescope to identify these possible black hole seeds. They discuss their findings in a paper that will appear in an upcoming issue of the Monthly Notices of the Royal Astronomical Society.
“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.”
Scientists believe a supermassive black hole lies in the center of nearly all large galaxies, including our own Milky Way. They have found that some of these supermassive black holes, which contain millions or even billions of times the mass of the sun, formed less than a billion years after the start of the universe in the Big Bang.
One theory suggests black hole seeds were built up by pulling in gas from their surroundings and by mergers of smaller black holes, a process that should take much longer than found for these quickly forming black holes.
These new findings suggest instead that some of the first black holes formed directly when a cloud of gas collapsed, bypassing any other intermediate phases, such as the formation and subsequent destruction of a massive star.
“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 researchers used computer models of black hole seeds combined with a new method to select candidates for these objects from long-exposure images from Chandra, Hubble and Spitzer.
The team found two strong candidates for black hole seeds. Both of these matched the theoretical profile in the infrared data, including being very red objects, and they also emit X-rays detected with Chandra. Estimates of their distance suggest they may have been formed when the universe was less than a billion years old
“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 to obtain further observations in X-rays and infrared to check whether these objects have more of the properties expected for black hole seeds. Upcoming observatories, such as NASA’s James Webb Space Telescope and the European Extremely Large Telescope, will aid in future studies by detecting the light from more distant and smaller black holes. Scientists currently are building the theoretical framework needed to interpret the upcoming data, with the aim of finding the first black holes in the universe.
“As scientists, we cannot say at this point that our model is ‘the one’,” said Pacucci. “What we really believe is that our model is able to reproduce the observations without requiring unreasonable assumptions.”
NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program while the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington.
NASA’s Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission, whose science operations are conducted at the Spitzer Science Center. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado.
For more on NASA’s Chandra X-ray Observatory, visit: http://www.nasa.gov/chandra
For more on NASA’s Hubble Space Telescope, visit: http://www.nasa.gov/hubble
For more on NASA’s Spitzer Space Telescope, visit: http://www.nasa.gov/spitzer
Spitzer Telescope Maps Super Earth’s Climate
Observations from NASA’s Spitzer Space Telescope have led to the first temperature map of a super-Earth planet — a rocky planet nearly two times as big as ours. The map reveals extreme temperature swings from one side of the planet to the other, and hints that a possible reason for this is the presence of lava flows.
 This animated illustration shows one possible scenario for the rocky exoplanet 55 Cancri e, nearly two times the size of Earth. New Spitzer data show that one side of the planet is much hotter than the other – which could be explained by a possible presence of lava pools. Credits: NASA/JPL-Caltech |
“Our view of this planet keeps evolving,” said Brice Olivier Demory of the University of Cambridge, England, lead author of a new report appearing in the March 30 issue of the journal Nature. “The latest findings tell us the planet has hot nights and significantly hotter days. This indicates the planet inefficiently transports heat around the planet. We propose this could be explained by an atmosphere that would exist only on the day side of the planet, or by lava flows at the planet surface.”
The toasty super-Earth 55 Cancri e is relatively close to Earth at 40 light-years away. It orbits very close to its star, whipping around it every 18 hours. Because of the planet’s proximity to the star, it is tidally locked by gravity just as our moon is to Earth. That means one side of 55 Cancri, referred to as the day side, is always cooking under the intense heat of its star, while the night side remains in the dark and is much cooler.
“Spitzer observed the phases of 55 Cancri e, similar to the phases of the moon as seen from the Earth. We were able to observe the first, last quarters, new and full phases of this small exoplanet,” said Demory. “In return, these observations helped us build a map of the planet. This map informs us which regions are hot on the planet.”
Spitzer stared at the planet with its infrared vision for a total of 80 hours, watching it orbit all the way around its star multiple times. These data allowed scientists to map temperature changes across the entire planet. To their surprise, they found a dramatic temperature difference of 2,340 degrees Fahrenheit (1,300 Kelvin) from one side of the planet to the other. The hottest side is nearly 4,400 degrees Fahrenheit (2,700 Kelvin), and the coolest is 2,060 degrees Fahrenheit (1,400 Kelvin).
The fact Spitzer found the night side to be significantly colder than the day side means heat is not being distributed around the planet very well. The data argues against the notion that a thick atmosphere and winds are moving heat around the planet as previously thought. Instead, the findings suggest a planet devoid of a massive atmosphere, and possibly hint at a lava world where the lava would become hardened on the night side and unable to transport heat.
“The day side could possibly have rivers of lava and big pools of extremely hot magma, but we think the night side would have solidified lava flows like those found in Hawaii,” said Michael Gillon, University of Liège, Belgium.
The Spitzer data also revealed the hottest spot on the planet has shifted over a bit from where it was expected to be: directly under the blazing star. This shift either indicates some degree of heat recirculation confined to the day side, or points to surface features with extremely high temperatures, such as lava flows.
Additional observations, including from NASA’s upcoming James Webb Space Telescope, will help to confirm the true nature of 55 Cancrie.
The new Spitzer observations of 55 Cancri are more detailed thanks to the telescope’s increased sensitivity to exoplanets. Over the past several years, scientists and engineers have figured out new ways to enhance Spitzer’s ability to measure changes in the brightness of exoplanet systems. One method involves precisely characterizing Spitzer’s detectors, specifically measuring “the sweet spot” — a single pixel on the detector — which was determined to be optimal for exoplanet studies.
“By understanding the characteristics of the instrument — and using novel calibration techniques of a small region of a single pixel — we are attempting to eke out every bit of science possible from a detector that was not designed for this type of high-precision observation,” said Jessica Krick of NASA’s Spitzer Space Science Center, at the California Institute of Technology in Pasadena.
NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.
For more information about Spitzer, visit: http://www.nasa.gov/spitzer
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