University of Arizona astronomers will host colleagues from Paris Observatory, the Massachusetts Institute of Technology and Lowell Observatory at UA telescopes for the not-to-be-missed event.
Arizona has a special tie to Pluto: Astronomer Clyde Tombaugh was working for Lowell Observatory in Flagstaff when he discovered the ninth planet in 1930. Tombaugh was the only American ever to discover a planet in our solar system. The International Astronomical Union ignited public and scientific controversy last August when it downgraded Pluto's status to a dwarf planet known as number 134340.
But whatever you call it, the object interests planetary scientists.
"Occultations are the only way we can monitor the atmosphere of Pluto from the Earth," said Professor William B. Hubbard of UA's Lunar and Planetary Laboratory, who is coordinating the UA campaign to observe the Pluto occultation.
Not only are the observations important to scientists studying Pluto's atmosphere, Hubbard said, they're important to NASA's $620 million New Horizons spaceprobe, which just flew by Jupiter and is on target to reach Pluto and the Kuiper belt in 2015. Previous observations of Pluto occultations have yielded surprising findings about Pluto's changing air pressure, for example, Hubbard said, "so it's going to be important to keep track of what Pluto is doing until the spacecraft gets there."
An occultation is like an eclipse. Just as the moon casts its shadow onto Earth when it passes directly in front of the sun, planets cast their shadows onto Earth when they pass directly in front of a star. Hubbard, Bruno Sicardy of the Paris Observatory and Faith Vilas, who is now director of the MMT Observatory, discovered Neptune's rings in the 1980s, before Voyager detected them, from ground-based observations made during a Neptune occultation.
In past decades, astronomers could typically expect a Pluto occultation only every five to 10 years, Sicardy said. But now Pluto is moving in front of the Milky Way, and astronomers may see one or two Pluto occultations a year because of the abundance of background stars.
"But even though there are now more than one of these events per year, we can't count on seeing them all because of cloudy weather, or because Pluto's shadow falls on Earth where there are no observatories," Sicardy said.
"This time, the event is observable by a region of the world populated with great telescopes -- the southwestern United States," Sicardy said. "To observe this in Arizona is like closing a big loop after more than 70 years. It's kind of like celebrating Pluto's discovery," he added.
Pluto has a diameter of 2,775 kilometers, or about 1,400 miles, and is almost 40 times farther from the sun than the Earth is. It will pass in front of the star in Sagittarius at 4 a.m. Arizona time (11 Universal Time) on Sunday, March 18. The occultation will last six minutes -- about 3 times longer than typical Pluto occultations -- giving telescopes as small as 50 centimeters (20 inches) time to record the event.
If the telescope is aligned in the exact line of sight with the star when Pluto eclipses the starlight, its lucky astronomers might see the "central flash" phenomenon. They would see a sudden brightening, a flash, while entirely in Pluto's shadow. That could give them important information on the shape of Pluto's atmosphere or its winds, as well as a thrill.
All the visible light cameras are fast readout cameras with good time resolution, said Lunar and Planetary Laboratory scientist Steve Larson. He'll observe with the 61-inch Kuiper Telescope in the Santa Catalina Mountains north of Tucson. "This will help provide accurate timings of ingress, egress and a central flash if we are situated right," he noted.
Participating UA astronomers and telescopes include:
? The UA/Smithsonian Institution's 6.5-meter (260-inch) MMT on Mount Hopkins. Steward Observatory astronomers Donald W. McCarthy and Craig Kulesa will use a wide-field infrared camera called "PISCES" that may spot clouds or haze if they exist in Pluto's atmosphere. At the same time, Susan Kern and Michael Person of MIT will use a "POETS" camera loaned by Lowell Observatory to observe at optical wavelengths. POETS is an acronym for Portable Occultation Eclipse and Transit System. http://www.mmto.org/
? Bruno Sicardy will use a camera from his Paris Observatory on the 90-inch (2.3 meter) Bok Telescope on Kitt Peak. His visible light camera takes 10 frames per second. The Bok Telescope is the largest operated soley by the UA Steward Observatory. http://james.as.arizona.edu/%7Epsmith/90inch/90inch.html
? Catalina Sky Survey Director Steve Larson of UA's Lunar and Planetary Laboratory and Thomas Widemann of the Paris Observatory will observe with Steward Observatory's 61-inch (1.6 meter) Kuiper Telescope in the Santa Catalina Mountains north of Tucson. http://james.as.arizona.edu/~psmith/61inch/
? Rick Hill of UA's Lunar and Planetary Laboratory and Henry Roe of Lowell Observatory will use UA's 60-inch (1.5 meter) telescope on Steward Observatory's Mount Lemmon site. http://james.as.arizona.edu/~psmith/60inch/
Contact InformationWilliam B. Hubbard 520-621-6942 email@example.com
Lori Stiles | University of Arizona
Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst
Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
27.03.2017 | Earth Sciences
27.03.2017 | Life Sciences
27.03.2017 | Life Sciences