Featured Research

from universities, journals, and other organizations

Astronomers View First Mutual Event For Uranus: One Satellite Passes In Front Of Another

Date:
May 28, 2007
Source:
Armagh Observatory
Summary:
Astronomers have made the first ever observation of one of the satellites of the planet Uranus passing in front of another. The observation was made on the night of 4th May using the robotic Faulkes Telescope South at Siding Spring Observatory, Australia.

Voyager images of Oberon (left) and Umbriel (right), two satellites of Uranus.
Credit: Images courtesy of NASA

An international team of astronomers led by Apostolos Christou at Armagh Observatory has made the first ever observation of one of the satellites of the planet Uranus passing in front of another. The observation was made on the night of 4th May by Marton Hidas and Tim Brown, of the Las Cumbres Observatory Global Telescope, Santa Barbara, California, using the robotic Faulkes Telescope South at Siding Spring Observatory, Australia. This work involves a collaboration between scientists at Siding Spring, Las Cumbres, Armagh and Cardiff University.

Related Articles


When one satellite passes in front of another, the phenomenon is known as an occultation; when one moves into the shadow of another it is an eclipse. Collectively, occultations and eclipses are called mutual events. These provide a means to determine the positions of the satellites with exceptional precision, better than any optical telescope, but they are rare. In the case of Uranus, a season of mutual events occurs just once every 42 years, each individual event lasting just a few minutes. At the time of the last Uranian mutual event season, Man had yet to walk on the Moon. Not surprisingly, no-one had successfully recorded any mutual event involving these extremely faint satellites, which are 3,000 million kilometres from Earth.

But this situation changed this month, when the Faulkes telescope observed the satellite Oberon (named after the “King of Shadows and Fairies” in Shakespeare's “A Midsummer Night's Dream”) occulting Umbriel (the “dusky melancholy sprite” in Alexander Pope's poem “The Rape of the Lock”). As Oberon's disc encroached upon Umbriel's, gradually blocking off Umbriel’s light, the combined brightness of the moons dropped by about a third.

Measurements of such changes in brightness, and comparison with models of the satellites' motions, allow astronomers to work out the masses of the moons and the effects of the shape of Uranus on their orbits, and to model their surface features. The current Uranian mutual-event season is expected to lead to some of the greatest advances in the study of the Uranian system since the flyby of the Voyager 2 spacecraft in 1986.

This observation kicks off a campaign extending from now into 2008 to observe the entire mutual event season. It highlights the value of the North and South Faulkes telescopes for recording rare, time-critical events. And because the telescopes have an educational focus, the data will eventually be used not just by astronomers but also by schools and schoolchildren worldwide.


Story Source:

The above story is based on materials provided by Armagh Observatory. Note: Materials may be edited for content and length.


Cite This Page:

Armagh Observatory. "Astronomers View First Mutual Event For Uranus: One Satellite Passes In Front Of Another." ScienceDaily. ScienceDaily, 28 May 2007. <www.sciencedaily.com/releases/2007/05/070527182019.htm>.
Armagh Observatory. (2007, May 28). Astronomers View First Mutual Event For Uranus: One Satellite Passes In Front Of Another. ScienceDaily. Retrieved October 30, 2014 from www.sciencedaily.com/releases/2007/05/070527182019.htm
Armagh Observatory. "Astronomers View First Mutual Event For Uranus: One Satellite Passes In Front Of Another." ScienceDaily. www.sciencedaily.com/releases/2007/05/070527182019.htm (accessed October 30, 2014).

Share This



More Space & Time News

Thursday, October 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Antares Liftoff Explosion

Raw: Antares Liftoff Explosion

AP (Oct. 29, 2014) Observers near Wallops Island recorded what they thought would be a routine rocket launch Tuesday night. What they recorded was a major rocket explosion shortly after lift off. (Oct 29) Video provided by AP
Powered by NewsLook.com
Raw: Russian Cargo Ship Docks at Space Station

Raw: Russian Cargo Ship Docks at Space Station

AP (Oct. 29, 2014) Just hours after an American cargo run to the International Space Station ended in flames, a Russian supply ship has arrived at the station with a load of fresh supplies. (Oct. 29) Video provided by AP
Powered by NewsLook.com
Journalist Captures Moment of Antares Rocket Explosion

Journalist Captures Moment of Antares Rocket Explosion

Reuters - US Online Video (Oct. 29, 2014) A space education journalist is among those who witness and record the explosion of an unmanned Antares rocket seconds after its launch. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
Rocket Explosion Under Investigation

Rocket Explosion Under Investigation

AP (Oct. 28, 2014) NASA and Orbital Sciences officials say they are investigating the explosion of an unmanned commercial supply rocket bound for the International Space Station. It blew up moments after liftoff Tuesday evening over the launch site in Virginia. (Oct. 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins