A team of scientists led by astronomers at the University of California, Riverside has used NASA’s Hubble Space Telescope and the W. M. Keck Observatory to uncover the long-suspected underlying population of galaxies that produced the bulk of new stars during the universe’s early years.
Galaxy Cluster Abell 1689 Credit: HST/STScI, H. Ford (JHU)The galaxies are the smallest, faintest, and most numerous galaxies ever seen in the remote universe, and were captured by Hubble deep exposures taken in ultraviolet light, and confirmed using the mighty Keck I telescope on the summit of Mauna Kea on the island of Hawaii.
Today, at 02:25HST, the planet Venus will pass through inferior conjunction, passing between the Earth and the Sun. Venus will remain hidden from view for another week, emerging in the dawn sky around the 18th. Maximum elongation will be on March 22nd at 46.6°W.
Unlike 2012 there will be no transit, from our point of view the planet will pass over 5° north of the Sun. The next transit will not occur until 2117.
University of Hawaii at Manoa astronomer Regina Jorgenson has obtained the first image that shows the structure of a normal galaxy in the early universe as captured by the W. M. Keck Observatory. The results were presented at the winter American Astronomical Society meeting being held this week near Washington, DC.
A map of the hydrogen emission from DLA2222-0946. Credit R. JorgensonThe galaxy, called DLA2222-0946, is so faint that it is virtually invisible at all but a few specific wavelengths. It is a member of a class of galaxies thought to be the progenitors of spiral galaxies like our own Milky Way.
These galaxies are known to contain most of the neutral gas that is the fuel for star formation, so they are an important tool for understanding star and galaxy formation and evolution. Discovered and classified over 30 years ago, they have been notoriously difficult to see directly.
Dr. Jorgenson, an NSF Astronomy and Astrophysics Postdoctoral Fellow at the University of Hawaii’s Institute for Astronomy, worked with Dr. Arthur Wolfe of the University of California, San Diego. They used the advanced technologies of the W. M. Keck Observatory on Mauna Kea to obtain the first-ever spatially resolved images of a galaxy of this type.
The galaxy was detected with the 10-meter, Keck I telescope fitted with OSIRIS and the Laser Guide Star Adaptive Optics system.
The Kepler team today reports on four years of observations from the W. M. Keck Observatory targeting Kepler’s exoplanet systems, announcing results this week at the American Astronomical Society meeting in Washington. These observations, from Keck Observatory on the summit of Mauna Kea, confirm that numerous Kepler discoveries are indeed planets and yield mass measurements of these enigmatic worlds that vary between Earth and Neptune in size.
Chart of Kepler planet candidates as of January 2014., credit NASA AmesMore than three-quarters of the planet candidates discovered by NASA’s Kepler spacecraft have sizes ranging from that of Earth to that of Neptune, which is nearly four times as big as Earth. Such planets dominate the galactic census but are not represented in our own solar system. Astronomers don’t know how they form or if they are made of rock, water or gas.
Using one of the two world’s largest telescopes at Keck Observatory in Hawaii, scientists confirmed 41 of the exoplanets discovered by Kepler and determined the masses of 16. With the mass and diameter in-hand, scientists could immediately determine the density of the planets, characterizing them as rocky or gaseous, or mixtures of the two.
Getting to and from the vehicles was done as quickly as possible, running from door to door. Not only were the temperatures as low as anyone could remember, the wind was adding to the issue, blowing at a steady 35mph. The temperatures reached -8°C (17°F) at night and never rose above freezing during the day. The ice is slowly sublimating in the dry air, but there is still too much on the domes for safe observing.
Now if the wind would obey the posted speed limit…
The remains of heavy ice sublimating in cold, dry air with steady 35mph winds
More than three-quarters of the planet candidates discovered by NASA’s Kepler spacecraft have sizes ranging from that of Earth to that of Neptune, which is nearly four times as big as Earth. Such planets dominate the galactic census but are not represented in our own solar system. Astronomers don’t know how they form or if they are made of rock, water or gas.
Artist’s rendition of the Kepler Spacecraft in orbit around the Sun peering at a distant solar system, press release image from the NASA Kepler websiteThe Kepler team today reports on four years of ground-based follow-up observations targeting Kepler’s exoplanet systems at the American Astronomical Society meeting in Washington. These observations confirm the numerous Kepler discoveries are indeed planets and yield mass measurements of these enigmatic worlds that vary between Earth and Neptune in size.
Included in the findings are five new rocky planets ranging in size from 10 to 80 percent larger than Earth. Two of the new rocky worlds, dubbed Kepler-99b and Kepler-406b, are both 40 percent larger in size than Earth and have a density similar to lead. The planets orbit their host stars in less than five and three days respectively, making these worlds too hot for life as we know it.
A major component of these follow-up observations was Doppler measurements of the planets’ host stars. The team measured the reflex wobble of the host star, caused by the gravitational tug on the star exerted by the orbiting planet. That measured wobble reveals the mass of the planet: the higher the mass of the planet, the greater the gravitational tug on the star and hence the greater the wobble.
