Since the mid-1990s, when the first planet around another sun-like star was discovered, astronomers have amassed an ever-expanding collection of nearly 3,500 confirmed exoplanets.
In a new Caltech-led study, researchers have classified these exoplanets in much the same way that biologists identify new animal species and found the majority of exoplanets fall into two distinct groups: rocky Earth-like planets and larger mini-Neptunes. The team used data from W. M. Keck Observatory and NASA’s Kepler mission.
“This is a major new division in the family tree of planets, analogous to discovering that mammals and lizards are distinct branches on the tree of life,” says Andrew Howard, professor of astronomy at Caltech and a principal investigator of the new research.
The lead author of the new study, to be published in The Astronomical Journal, is Benjamin J. (B. J.) Fulton, a graduate student in Howard’s group.
In essence, their research shows that our galaxy has a strong preference for either rocky planets up to 1.75 times the size of Earth or gas-enshrouded mini-Neptune worlds, which are from 2 to 3.5 times the size of Earth (or somewhat smaller than Neptune). Our galaxy rarely makes planets with sizes in between these two groups.
“Astronomers like to put things in buckets,” says Fulton. “In this case, we have found two very distinct buckets for the majority of the Kepler planets.”
In the ten years I have lived on island I have never missed an AstroDay. This year was no change to that streak, I volunteered to do the last shift on the Keck Observatory table, 2-4pm. Show up at lunchtime, enjoy the activities myself for a while, say hi to everyone I know there, then do my shift on the table… Good plan.
We were using a thermal camera for our primary activity. Instead of borrowing the fancy, and very expensive, FLIR camera from the summit, our outreach group has bought one of the little iPad thermal cameras from Seek Thermal.
I was pleasantly surprised with this little thermal camera, it does a nice job costing only a few hundred dollars. Using the iPad linked to a large display using AirPlay the setup worked quite well in practice. I could handle the camera with no wires to tether me to one place.
Seven years of meticulous observing have resulted in a cosmic discovery that comes from an era dating back 13.1 billion years, giving scientists a detailed glimpse of what may have happened just after the Big Bang.
Using the world-class W. M. Keck Observatory on Maunakea, Hawaii, an international team of astronomers from the United States, Australia, and Europe has confirmed the existence of one of the most distant galaxies in the universe.
To characterize the faint galaxy, the discovery team, led by Austin Hoag, a University of California, Davis physics graduate student, used MOSFIRE, the most in-demand instrument on the 10-meter Keck I telescope.
What makes this galaxy extraordinary is that it is ordinary. It is thought to be a common galaxy at that distance and age of the universe. However, such galaxies would normally be too faint to detect. The astronomers used a method called gravitational lensing to magnify the galaxy so they could study it.
“Most objects that we’ve seen at that distance are extremely bright, and probably rare compared to other galaxies,” said Hoag. “We think this galaxy is much more representative of other galaxies of its time.”
W. M. Keck Observatory overnight captured the very first successful science data from its newest, cutting-edge instrument, the Keck Cosmic Web Imager (KCWI).
KCWI captures three-dimensional data, as opposed to the traditional two-dimensional image or spectrum of conventional instruments. In a single observation, it records an image of the object at multiple wavelengths allowing scientists to explore both the spatial dimension (as in an image) and the spectral dimension (or color) of an object.
“I’m thrilled to see this new instrument,” said Keck Observatory Director Hilton Lewis. “It takes years to design and build these very sophisticated instruments. KCWI is a superb example of the application of the most advanced technology to enable the hardest science. I believe it has the potential to transform the science that we do, and continue to keep Keck Observatory right at the forefront of astronomical research.”
KCWI is extremely sensitive, specifically designed to capture high-resolution spectra of ultra-faint celestial bodies with unprecedented detail. It is able to differentiate even the slightest changes in spectral color with a great degree of accuracy.
This powerful capability is key for astronomers because a highly-detailed spectral image allows them to identify a cosmic object’s characteristics, including its temperature, motion, density, mass, distance, chemical composition, and more.
An international team of astronomers has, for the first time, spotted a massive, inactive galaxy from a time when the Universe was only 1.65 billion years old. This rare discovery, made using the world-class W. M. Keck Observatory on Maunakea, Hawaii, could change the way scientists think about the evolution of galaxies.
This research publishes today in the journal Nature, with Professor Karl Glazebrook, director of Swinburne’s Centre for Astrophysics and Supercomputing , as the lead author. To characterize the faint galaxy, the discovery team used MOSFIRE, the most in-demand instrument on the 10-meter Keck I telescope.
“This observation was only possible due to the extreme sensitivity of the new MOSFIRE spectrograph,” said Glazebrook. “It is the absolute best in the world for faint near-IR spectra by a wide margin. Our team is indebted to the accomplishment of Chuck Steidel, Ian McClean, and all the Keck Observatory staff for building and delivering this remarkable instrument.”
Astronomers expect most galaxies from this epoch to be low-mass minnows, busily forming stars. However, this galaxy is ‘a monster’ and inactive.
Across the room from my desk is a large cabinet full of blueprints and sepia prints. Stacks of large prints that represent the original drawings from which the W. M. Keck Observatory was constructed. Floor plans, foundation plans, the structural steel of the telescope itself.
The prints are in many ways works of art. Often drawn by hand these old prints represent a lost skill, the art of the draughtsman from before computers irreversibly changed the profession. Impeccably neat lettering, an arcane menagerie of symbols, coded shading to represent different materials, it takes time just to learn to read these drawings properly.
A trip past the sun may have selectively altered the production of one form of water in a comet – an effect not seen by astronomers before, a new NASA study suggests.
Astronomers from NASA’s Goddard Space Flight Center in Greenbelt, Maryland, observed the Oort cloud comet C/2014 Q2, also called Lovejoy, when it passed near Earth in early 2015. Through NASA’s partnership in the W. M. Keck Observatory on Mauna Kea, Hawaii, the team observed the comet at infrared wavelengths a few days after Lovejoy passed its perihelion – or closest point to the sun.
Scientists from NASA’s Goddard Center for Astrobiology observed the comet C/2014 Q2 – also called Lovejoy – and made simultaneous measurements of the output of H2O and HDO, a variant form of water. This image of Lovejoy was taken on Feb. 4, 2015 – the same day the team made their observations and just a few days after the comet passed its perihelion, or closest point to the sun.
An international team of astronomers has released the largest ever compilation of exoplanet-detecting observations made using a technique called the radial velocity method. By making the data public, the team is offering unprecedented access to one of the best exoplanet searches in the world.
The data were gathered as part of a two-decade planet-hunting program using a spectrometer called HIRES, built by UC Santa Cruz astronomer Steven Vogt and mounted on the 10-meter Keck-I telescope at the W. M. Keck Observatory atop Mauna Kea in Hawaii.
“HIRES was not specifically optimized to do this type of exoplanet detective work, but has turned out to be a workhorse instrument of the field,” said Vogt, a professor emeritus of astronomy and astrophysics. “I am very happy to contribute to science that is fundamentally changing how we view ourselves in the universe.”