Tag: Keck

The future of astronomy, as seen by PBS News in 1991

6:01 pm

An evening pause: Today is the 75th anniversary of the moment astonomers took the lens cap off the Hale Telescope at Palomar, what astronomers call “first light.” In honor of this anniversary, tonight’s evening pause is a somewhat well-done news piece produced by PBS in 1991, describing the state of ground-based astronomy at that time, which was actually another key moment in the history of astronomy. After decades of no advancement following the Hale telescope, the field was about to burst out with a whole new set of telescopes exceeding it significantly, based on new technologies. We today have become accustomed to those new telescopes, but in 1991 they were still incomplete or on the drawing board.

This was also after the launch of Hubble but before it was fixed, so this moment was also a somewhat dark time for astronomy in general. Watching this news piece gives you a sense of history, as seen by those living at that time. It also lets you see some good examples of the standard tropes of reporters as well as some astronomers. They always say this new telescope (whatever and whenever it is) is going to allow us to discover the entire history of the universe, even though it never can, and never will.

Hat tip Mike Nelson.

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Astronomers detect white dwarf star with two faces

9:13 am

The uncertainty of science: Astronomers using ground-based telescopes have discovered a white dwarf star in which the surface chemistry of its two hemispheres are very different, one strongly dominated by hydrogen while the other instead dominated by helium.

The team used the Low Resolution Imaging Spectrometer (LRIS) on the Keck I Telescope to view Janus in optical wavelengths (light that our eyes can see) as well as the Near-Infrared Echellette Spectrograph (NIRES) on the Keck II Telescope to observe the white dwarf in infrared wavelengths. The data revealed the white dwarf’s chemical fingerprints, which showed the presence of hydrogen when one side of the object was in view (with no signs of helium), and only helium when the other side swung into view.

The article lists a lot of proposed explanations, most of which suggest the star’s magnetic field is acting to segregate the materials. All assume these observations are certain and that there is no mixing at all, something we should doubt considering the resolution of the data (a mere point that is rotating).

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More direct images released of exoplanet 87.5 light years away

9:56 am

Keck images of exoplanet over time

The Keck Observatory in Hawaii has now released its own image of the exoplanet AF Leporis b, following up the images produced by the Very Large Telescope (VLT) released in February.

The direct images Franson’s team captured revealed that AF Lep b is about three times the mass of Jupiter and orbits AF Leporis, a young Sun-like star about 87.5 light-years away. They took a series of deep images of the planet starting in December 2021; two other teams also captured images of the same planet since then.

What make the Keck observations most interesting is that they captured over time the motion of the exoplanet as it orbited its star. The two images to the right show this motion.

The paper, available here, was published today in Astrophysical Journal Letters. This particular star also has a debris disk surrounding it, suggesting it is a young solar system still in the process of forming. From the paper’s conclusion:

AF Lep joins other young planet hosts with debris disks such as β Pic, HR 8799, HD 206893, and HD 95086, reinforcing indications of a higher frequency of long-period planets orbiting stars hosting debris disks.

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First binary quasar found

9:48 am

Double quasar as seen by the Hubble Space Telescope
Double quasar as seen by the Hubble Space Telescope

Using a suite of telescopes on the ground and in orbit, astronomers have found the first galaxy made up of two quasars, supermassive black holes that are very active in eating material from around them.

ESA’s (European Space Agency) Gaia space observatory first detected the unresolved double quasar, capturing images that indicate two closely aligned beacons of light in the young universe. Chen and his team then used NASA’s Hubble Space Telescope to verify the points of light were in fact coming from a pair of supermassive black holes.

Multi-wavelength observations followed; using Keck Observatory’s second generation Near-Infrared Camera (NIRC2) paired with its adaptive optics system, as well as Gemini North, NASA’s Chandra X-ray Observatory, and the Very Large Array network of radio telescopes in New Mexico, the researchers confirmed the double quasar was not two images of the same quasar created by gravitational lensing.

The two quasars are estimated to be only about 10,000 light years apart. Scientists estimate that this galaxy is about ten billion light years away, and exists in this state only about three billion years after the Big Bang.

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China to build giant ground-based optical telescope

9:45 am

China has announced its plan to build ground-based multi-segmented optical telescope, similar in design to the 10-meter Keck Telescope in Hawaii.

Peking University wants to build the largest optical telescope in Asia and close the gap in astronomy capabilities with the rest of the world.

The project aims to create an initial telescope with an aperture of 19.7 feet (6 meters) by 2024; the mirror will be expanded to 26.2 feet (8 m) by 2030. The project, which in English is called the Expanding Aperture Segmented Telescope (EAST), is being led by Peking University.

Like Keck, the primary mirror would be made of smaller segments, fitted together to create the larger mirror. While not as large as Keck, EAST would be among the largest in the world.

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Webb and Keck telescopes track clouds on Titan

11:08 am

Clouds on Titan
Click for original image.

Astronomers have used the Webb Space Telescope and the Keck Observatory in Hawaii to take infrared images days apart of the evolving clouds on the Saturn moon Titan.

The false-color infrared images to the right are those observations. From the press release:

As part of their investigation of Titan’s atmosphere and climate, Nixon’s team used JWST’s Near-Infrared Camera (NIRCam) to observe the moon during the first week of November. After seeing the clouds near Kraken Mare, the largest known liquid sea of methane on the surface of Titan, they immediately contacted the Keck Titan Observing Team to request follow-up observations.

“We were concerned that the clouds would be gone when we looked at Titan a day later with Keck, but to our delight there were clouds at the same positions on subsequent observing nights, looking like they had changed in shape,” said Imke de Pater, emeritus professor of astronomy at the University of California, Berkeley, who leads the Keck Titan Observing Team.

Using Keck Observatory’s second generation Near-Infrared Camera (NIRC2) in combination with the Keck II Telescope’s adaptive optics system, de Pater and her team observed one of Titan’s clouds rotating into and another cloud either dissipating or moving out of Earth’s field of view due to Titan’s rotation.

These images only increase my mourning for a Saturn orbiter. Since the end of Cassini’s mission in 2017, we have essentially been blind to the ringed planet and its many moons. These images, while producing excellent data, also illustrate well what we have lost.

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