Wednesday, October 19, 2011

Youngest Planet Seen As It’s Forming

Kamuela, HI – The first direct image of a planet in the process of forming around its star has been captured by astronomers who combined the power of the 10-meter Keck telescopes with a bit of optical sleight of hand.

What astronomers are calling LkCa 15 b, looks like a hot “protoplanet” surrounded by a swath of cooler dust and gas, which is falling into the still-forming planet. Images have revealed that the forming planet sits inside a wide gap between the young parent star and an outer disk of dust.

“LkCa 15 b is the youngest planet ever found, about 5 times younger than the previous record holder,” said astronomer Adam Kraus of the University of Hawaii’s Institute for Astronomy. “This young gas giant is being built out of the dust and gas. In the past, you couldn’t measure this kind of phenomenon because it’s happening so close to the star. But, for the first time, we’ve been able to directly measure the planet itself as well as the dusty matter around it.”

Kraus will be presenting the discovery at an Oct. 19 meeting at NASA’s Goddard Space Flight Center. The meeting follows the acceptance of a research paper on the discovery by Kraus and Michael Ireland (of Macquarie University and the Australian Astronomical Observatory), in The Astrophysical Journal (available at http://arxiv.org/abs/1110.3808)

Figure 1 Left: The transitional disk around the star LkCa15. All of the light at this wavelength is emitted by cold dust in the disk. the hole in the center indicates an inner gap with radius of about 55 times the distance from the Earth to the Sun. Right: An expanded view of the central part of the cleared region, showing a composite of two reconstructed images (blue: 2.1 microns, from November 2010; red: 3.7 microns) for LkCa 15. The location of the central star is also marked.

The optical sleight of hand used by the astronomers is to combine the power of Keck’s Adaptive Optics with a technique called aperture mask interferometry. The former is the use of a deformable mirror to rapidly correct for atmospheric distortions to starlight. The latter involves placing a small mask with several holes in the path of the light collected and concentrated by a giant telescope. With that, the scientists can manipulate the light waves.

“It’s like we have an array of small mirrors,” said Kraus. “We can manipulate the light and cancel out distortions.” The technique allows the astronomers to cancel out the bright light of stars. They can then resolve disks of dust around stars and see gaps in the dusty layers where protoplanets may be hiding.

“Interferometry has actually been around since the 1800’s, but through the use of adaptive optics has only been able to reach nearby young suns for about the last 7 years.” said Dr. Ireland. “Since then we’ve been trying to push the technique to its limits using the biggest telescopes in the world, especially Keck.”

The discovery of LkCa 15 b began as a survey of 150 young dusty stars in star forming regions. That led to the more concentrated study of a dozen stars.

“LkCa 15 was only our second target, and we immediately knew we were seeing something new,” said Kraus. “We could see a faint point source near the star, so thinking it might be a Jupiter-like planet we went back a year later to get more data.”

Figure 2 The location of LkCa 15 can be found using this chart.

In further investigations at varying wavelengths, the astronomers were intrigued to discover that the phenomenon was more complex than a single companion object.

“We realized we had uncovered a super Jupiter-sized gas planet, but that we could also measure the dust and gas surrounding it. We’d found a planet, perhaps even a future solar system at its very beginning” said Kraus.

Drs. Kraus and Ireland plan to continue their observations of LkCa 15 and other nearby young stars in their efforts to construct a clearer picture of how planets and solar systems form.

# # #

The W. M. Keck Observatory operates two 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Big Island of Hawaii. The twin telescopes feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectroscopy and a world-leading laser guide star adaptive optics system which cancels out much of the interference caused by Earth’s turbulent atmosphere. The Observatory is a private 501(c) 3 non-profit organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.

Source: "Youngest Planet Seen As It's Forming." W. M. Keck Observatory. 2011. Web. 19 Oct. 2011. <http://www.keckobservatory.org/news/first_close-up_view_of_a_planet_being_formed/>

Saturday, October 8, 2011

TAKE ACTION ALERT! Tell the White House to Let NASA Explore Mars

TAKE ACTION ALERT!
Tell the White House to Let NASA Explore Mars

The October 12 deadline can not be moved.
Exomars
take action
The future of NASA’s – and the world’s -- exploration of Mars is hanging by a thread. And that thread may soon be cut by the White House Office of Management and Budget (OMB.)

I am writing you to ask that you take immediate action to prevent what could be a fatal blow to Mars exploration for the foreseeable future. Please write to John Holdren, the President’s Science Advisor, and ask him to support NASA’s Mars exploration program.

Right now, the OMB is considering whether to let NASA accept an offer of partnership -- and more than $1 billion dollars -- from the European Space Agency (ESA) so that the two space agencies can work together to launch a mission to Mars in 2016 and to follow it with a 2018 mission that would lay the groundwork for the long-sought Mars Sample Return.

To transfer the money, ESA is asking NASA for a letter committing the U.S. space agency to a solid partnership with the European agency. But NASA is an agency of the U.S. Administration and must do as it is told by powers like OMB–and it appears that that White House office is reluctant to let NASA make that commitment.

Scott Hubbard, former “Mars Czar” for NASA, summarizes the situation: “The European Space Agency is willing to put €850 million ($1.16 billion) to collaborate with us. But for reasons unknown, somewhere in the administration somebody is refusing to release the letter that would allow the head of ESA to collaborate with NASA Administrator Charles Bolden. Why on Earth would you refuse to allow over $1 billion of funding? It borders on the irresponsible.”

Mars exploration is expensive – we all understand that. It has reached the point where no one nation – not even the United States -- can afford to do it alone. That’s exactly why ESA has made this offer to share the cost.

If that offer is rejected, it will cause chaos in Mars exploration programs around the world. All the careful plans so painstakingly developed between NASA and ESA will come to naught.

Humanity’s exploration of Mars will be put on hold for the foreseeable future.

We can’t let that happen! And we have to act now!

Please, today, contact John Holdren at the Office of Science and Technology Policy and ask him to intervene and let NASA send that letter to ESA. The ESA Ministerial Council is meeting on October 12 and, if they don’t see that letter from NASA by then, they may order ESA to back out of is collaboration with NASA to explore Mars.

If you want to see Mars explored, please take action now.

Thank you.
bill
Bill Nye
Executive Director
Planetary Society
85 S. Grand Ave., Pasadena, CA 91105