A principal component analysis of quasar UV spectra at z  ~  3?

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Authors: I. Pâris, P. Petitjean, E. Rollinde, E. Aubourg, N. Busca, R. Charlassier, T. Delubac, J.-Ch. Hamilton, J.-M. Le Goff, N. Palanque-Delabrouille, S. Peirani, Ch. Pichon, J. Rich, M. Vargas-Magaña and Ch. Yèche.<br />Astronomy & Astrophysics Vol. 530 , page A50<br />Published online: 06/05/2011<br />
Keywords:
methods: numerical ; intergalactic medium ; quasars: absorption lines ; quasars: emission lines.

Reducing star leakage with a nuller coronagraph

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Authors: C. Aime, Y. Rabbia, A. Carlotti and G. Ricort.<br />Astronomy & Astrophysics Vol. 530 , page A52<br />Published online: 06/05/2011<br />
Keywords:
instrumentation: high angular resolution ; instrumentation: interferometers ; techniques: high angular resolution ; techniques: interferometric ; methods: analytical.

Detection of CH+ emission from the disc around HD 100546???

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Authors: W.-F. Thi, F. Ménard, G. Meeus, C. Martin-Zaïdi, P. Woitke, E. Tatulli, M. Benisty, I. Kamp, I. Pascucci, C. Pinte, C. A. Grady, S. Brittain, G. J. White, C. D. Howard, G. Sandell and C. Eiroa.<br />Astronomy & Astrophysics Vol. 530 , page L2<br />Published online: 28/04/2011<br />
Keywords:
protoplanetary disks ; astrochemistry.

Observation of H2O in a strongly lensed Herschel-ATLAS source at z = 2.3?

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Authors: A. Omont, R. Neri, P. Cox, R. Lupu, M. Guélin, P. van der Werf, A. Weiß, R. Ivison, M. Negrello, L. Leeuw, M. Lehnert, I. Smail, A. Verma, A. J. Baker, A. Beelen, J. E. Aguirre, M. Baes, F. Bertoldi, D. L. Clements, A. Cooray, K. Coppin, H. Dannerbauer, G. De Zotti, S. Dye, N. Fiolet, D. Frayer, R. Gavazzi, D. Hughes, M. Jarvis, M. Krips, M. J. Micha?owski, E. J. Murphy, D. Riechers, S. Serjeant, A. M. Swinbank, P. Temi, M. Vaccari, J. D. Vieira, R. Auld, B. Buttiglione, A. Cava, A. Dariush, L. Dunne, S. A. Eales, J. Fritz, H. Gomez, E. Ibar, S. Maddox, E. Pascale, M. Pohlen, E. Rigby, D. J. B. Smith, J. Bock, C. M. Bradford, J. Glenn, K. S. Scott and J. Zmuidzinas.<br />Astronomy & Astrophysics Vol. 530 , page L3<br />Published online: 28/04/2011<br />
Keywords:
galaxies: high-redshift ; galaxies: starburst ; galaxies: active ; infrared: galaxies ; submillimeter: galaxies ; radio lines: galaxies.

Dawn’s First Glimpse of Vesta

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The Dawn Spacecraft, launched September 27, 2007 (and getting a gravity boost from Mars in February 2009), is headed for the asteroid Vesta and the dwarf planet Ceres.

NASA/JPL Dawn trajectory

This next image, processed to show the true size of the giant asteroid Vesta, shows Vesta in front of a spectacular background of stars.  NASA got this image May 3rd:

NASA/JPL Dawn

“Since Vesta is so bright that it outshines its starry background, Dawn team members commanded a long exposure time to make the stars visible. They corrected the resulting exaggerated size of Vesta by superimposing a short exposure image of the target asteroid, showing its true size. Vesta is the small, bright pearl in the middle of the image.”  (NASA)

Isn’t that great?  Here’s the same image, without the processing:

NASA/JPL Dawn

“This image shows the first, unprocessed image obtained by NASA’s Dawn spacecraft of the giant asteroid Vesta in front of a background of stars. It was obtained by Dawn’s framing camera on May 3, 2011, from a distance of about 1.2 million kilometers, or 750,000 miles.” (NASA)

Here’s what NASA had to say about Dawn’s adventures:

NASA Dawn Spacecraft Captures First Image Of Nearing Asteroid

WASHINGTON — NASA’s Dawn spacecraft has obtained its first image of the giant asteroid Vesta, which will help fine-tune navigation during its approach. Dawn expects to achieve orbit around Vesta on July 16, when the asteroid is about 117 million miles from Earth.

The image from Dawn’s framing cameras was taken on May 3 when the spacecraft began its approach and was approximately 752,000 miles (1.21 million km) from Vesta. The asteroid appears as a small, bright pearl against a background of stars. Vesta also is known as a protoplanet, because it is a large body that almost formed into a planet.

“After plying the seas of space for more than a billion miles, the Dawn team finally spotted its target,” said Carol Raymond, Dawn’s deputy principal investigator at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif. “This first image hints of detailed portraits to come from Dawn’s upcoming visit.”

Vesta is 330 miles (530 km) in diameter and the second most massive object in the asteroid belt. Ground- and space-based telescopes obtained images of the bright orb for about two centuries, but with little surface detail.

Mission managers expect Vesta’s gravity to capture Dawn in orbit on July 16. To enter orbit, Dawn must match the asteroid’s path around the sun, which requires very precise knowledge of the body’s location and speed. By analyzing where Vesta appears relative to stars in framing camera images, navigators will pin down its location and enable engineers to refine the spacecraft’s trajectory.

Dawn will start collecting science data in early August at an altitude of approximately 1,700 miles (2,700 km) above the asteroid’s surface. As the spacecraft gets closer, it will snap multi-angle images allowing scientists to produce topographic maps. Dawn will later orbit at approximately 120 miles (200 km) to perform other measurements and obtain closer shots of parts of the surface. Dawn will remain in orbit around Vesta for one year. After another long cruise phase, Dawn will arrive in 2015 at its second destination, Ceres, an even more massive body in the asteroid belt.

Gathering information about these two icons of the asteroid belt will help scientists unlock the secrets of our solar system’s early history. The mission will compare and contrast the two giant asteroids shaped by different forces. Dawn’s science instruments will measure surface composition, topography and texture. Dawn also will measure the tug of gravity from Vesta and Ceres to learn more about their internal structures. The spacecraft’s full odyssey will take it on a 3-billion-mile (5-billion-km) journey, which began with its launch in September 2007.

Dawn’s mission to Vesta and Ceres is managed by JPL for NASA’s Science Mission Directorate in Washington. Dawn is a project of the directorate’s Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Ala.

The University of California in Los Angeles is responsible for overall Dawn mission science. Orbital Sciences Corp. of Dulles, Va., designed and built the spacecraft. The framing cameras were developed and built under the leadership of the Max Planck Institute for Solar System Research in Katlenburg-Lindau in Germany, with significant contributions by the German Aerospace Center (DLR) Institute of Planetary Research in Berlin and in coordination with the Institute of Computer and Communication Network Engineering in Braunschweig. The framing camera project is funded by NASA, the Max Planck Society and DLR.

Jupiter and Venus

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Venus and Jupiter pair up in the morning sky. This is looking east at 04:45. Click for May 12 pairing.

 

If you can get outside before daylight tomorrow and for the next few days you can get a look at the nice Jupiter/Venus pairing in the east.  Before daylight means after about 04:30 and about 05:00.  If you go out at 05:30 like I did this morning it will be too light out (in the northern hemisphere at least).  Pity too because this morning they were pretty close together.  Given the topography here the planets might not clear the mountain in time for me to see them anyway.

The images give you a representation of what you will see. The picture shows this morning and if you click it you will get tomorrow.  You will notice they spread out a little and that trend will continue as the days go by.  Venus will be somewhat brighter than Jupiter and both will be the brightest thing in the east provided the sun isn’t up.

I’ve been good about getting outside between 03:00 and 03:40. This morning the sky was amazing, I spent my time looking at Sagittarius, Scorpio and Antares. They are low in my southern horizon if you are up and about at such hours you should get a good look at them.

I kind of like the My Favorite Astronomer theme, I have two.  I will share one tomorrow.