Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. 24/7 Space News .




EXO WORLDS
Direct Infrared Image Of An Arm In Disk Demonstrates Transition To Planet Formation
by Staff Writers
Tokyo, Japan (SPX) Feb 11, 2013


Subaru Telescope's near-infrared (1.6 um) image of the protoplanetary disk around the young star J 1604. A black circular mask covers the bright, saturated light from the central star. The gauges for distance are in astronomical units and arc seconds. (Abbreviated as AU, an astronomical unit is the distance between the Sun and Earth. Abbreviated as arcsec, an arc second is 1/3600 of a degree.) Prominent features include the hole (white dotted line) in the disk; the arm extending over the hole (on the right); and the asymmetric dip (on the left). Click here for the image without labels. (Credit: The Graduate University for Advanced Studies and the National Astronomical Observatory of Japan). For a larger version of this image please go here.

An international team of astronomers led by Satoshi Mayama (Graduate University for Advanced Studies, Japan) and Ruobing Dong (Princeton University, U.S.A.) has made observations with the Subaru Telescope and captured the first vivid infrared image of a curved arm of dust extending over a hole on a disk around a young star - 2MASS J16042165-2130284 (J1604).

This feature indicates the probable existence of unseen planets within the hole. The image shows the dynamic environment in which planets may be born and gives information about constraints on the distance at which planets can form from a central star [Figure 1].

Research over the past two decades has confirmed that new stars are often surrounded by disks of dense gas and dust ("protoplanetary disks") from which planets form. A central star enters an active phase of planet building when it is a few million years old.

During this period, newborn planets may deplete some of the gas and dust in the disk, producing a hole within it, although the outer ring remains.

However, the debatable origins of the hole require direct observation to confirm this process. Direct imaging of the structures that indicate planet building inside of the hole have rarely occurred - until now.

The current team's research, a part of the Strategic Explorations of Exoplanets and Disks with Subaru (SEEDS) Project [Note 1], is filling in the observational gaps in this relatively unexplored area.

The team used the high-resolution infrared camera HiCIAO (High Contrast Instrument for the Subaru Next Generation Adaptive Optics) mounted on the 8.2-m Subaru Telescope in April 2012 to observe the young star J1604, which has a mass similar to the Sun's; it is located in the Upper Scorpius star-forming region at a distance of 470 light-years and is estimated to be 3.7 million years (Myr) old.

The researchers captured a very high-resolution (0.07 arc second) near-infrared image of its protoplanetary disk, which shows dust particles that scatter the light from the central star.

The disk has some interesting features: a large hole with an asymmetric dip in the disk and a curved arm extending over the hole.

This is the first vivid infrared image of such an arm in observations of the disks around young stars, and it also marks the first detection of an arm of dust that could lead to the formation of Earth-like rocky planets [Note 2]. The arm emerges from the inner edge of the western side of the disk, begins to extend inward, and then curves to the northeast.

Based on their detailed modeling, the team estimates that the radius of the disk's inner edge is 63 AU; its inclination is 10 degrees; and the length of the arm is 50 AU. Their measurements of the surface brightness of the gap show that it drops by a factor of five when compared with the rest of the disk.

Characteristics of the hole in the disk and the arm over it indicate the possible presence of unseen planets within the hole. The width and depth of the observed hole conform to the size of a hole that planets would create according to current theories of planet formation. The researchers' calculations suggest that the hole in this disk might mark the presence of at least one planet at 40 to 50 AU from the central star.

Current theories also predict that the gravity of a planet could produce a curved arm in a disk. Because the shape of the arm in the Subaru Telescope image shared features in line with theoretical predictions, the team concluded that unseen planets could explain its structure. Overall, these findings identify constraints on planet formation at certain distances from the central star [Figure 2].

The high-resolution image from these scientists' research at Subaru Telescope clearly illustrates the dynamic context in which planets are born. These kinds of detailed images of a face-on disk become perfect laboratories for astronomers to test and refine their theoretical models of planet formation.

[1] The SEEDS Project began in 2009 for a five-year period using 120 observing nights at Subaru Telescope, located at the summit of Mauna Kea on the island of Hawaii. The goal of the project is to explore hundreds of nearby stars in an effort to directly image extrasolar planets and protoplanetary/debris disks that surround less massive stars like the Sun. Principal investigator Motohide Tamura (NAOJ) leads the project.

[2] A January 2, 2013, article in Nature reported that the ALMA telescope resolved a submillimeter image of the disk of another object, HD 142527, which showed similar arm-like structures in its disk. However, the image displays streams of gas rather than dust particles flowing across the gap in the disk. These researchers suggest that the arm may indicate the presence of unseen planets, because giant planets may be using the gas as they grow within the disk.

Mayama, S. et al. December 2012, Astrophysical Journal Letter 760, L26, "Subaru Imaging of Asymmetric Features in a Transitional Disk in Upper Scorpius." Core members of this research team are S. Mayama, J. Hashimoto, T. Muto, T. Tsukagoshi, N. Kusakabe, M. Kuzuhara, Y. Takahashi, T. Kudo, R. Dong, M. Fukagawa, M. Takami, M. Momose, J. P. Wisniewski, K. Follette, and M. Tamura.

.


Related Links
Subaru Telescope
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





EXO WORLDS
Kepler Data Suggest Earth-size Planets May Be Next Door
Pasadena CA (JPL) Feb 08, 2013
Using publicly available data from NASA's Kepler space telescope, astronomers at the Harvard-Smithsonian Center for Astrophysics estimate that six percent of red dwarf stars in the galaxy have Earth-size planets in the "habitable zone," the range of distances from a star where the surface temperature of an orbiting planet might be suitable for liquid water. The majority of the sun's closes ... read more


EXO WORLDS
Building a lunar base with 3D printing

US, Europe team up for moon fly-by

Russia to Launch Lunar Mission in 2015

US, Europe team up for moon fly-by

EXO WORLDS
How The World's Saltiest Pond Gets Its Salt; Implications For Water On Mars

Lockheed Martin Completes Assembly, Begins Environmental Testing of NASA's MAVEN Spacecraft

NASA Curiosity Rover Collects First Martian Bedrock Sample

Sampling Several Rock Targets

EXO WORLDS
Supersonic skydiver even faster than thought

Ahmadinejad says ready to be Iran's first spaceman

Iran's Bio-Capsule Comes Back from Space

A Hero For Humankind: Yuri Gagarin's Spaceflight

EXO WORLDS
Reshuffle for Tiangong

China to launch 20 spacecrafts in 2013

Mr Xi in Space

China plans manned space launch in 2013: state media

EXO WORLDS
Progress docks with ISS

NASA to Send Inflatable Pod to International Space Station

ISS to get inflatable module

ESA workhorse to power NASA's Orion spacecraft

EXO WORLDS
Ariane 5 Arrives At Kourou For 4th Automated Transfer Vehicle Mission

Rocketdyne Powers Atlas 5 Upper Stage, Placing New Landsat In Orbit

Arianespace Launches Six Globalstar Birds Using Starsem Soyuz

Final checkout underway for the Starsem Soyuz launch with Globalstar spacecraft

EXO WORLDS
Direct Infrared Image Of An Arm In Disk Demonstrates Transition To Planet Formation

Kepler Data Suggest Earth-size Planets May Be Next Door

Earth-like planets may be closer than thought: study

Are Super-Earths Actually Mini-Neptunes?

EXO WORLDS
New classes of magnetoelectric materials promise advances in computing technology

Mercury contamination in water can be detected with a mobile phone

Scientists team with business innovators to solve 'big data' bottleneck

Looking out for lasers




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement