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.

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 September 14, 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 September 14, 2014).

Share This



More Space & Time News

Sunday, September 14, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

International Space Station Crew Returns Safely To Earth

International Space Station Crew Returns Safely To Earth

Newsy (Sep. 11, 2014) The three-man crew touched down in Kazakhstan Wednesday after more than five months of science experiments in orbit. Video provided by Newsy
Powered by NewsLook.com
Solar Storm To Hit This Weekend, Scientists Not Worried

Solar Storm To Hit This Weekend, Scientists Not Worried

Newsy (Sep. 11, 2014) Two solar flares which erupted in our direction this week will arrive this weekend. The resulting solar storm will be powerful but not dangerous. Video provided by Newsy
Powered by NewsLook.com
Solar Flare Surges Off Sun

Solar Flare Surges Off Sun

Reuters - US Online Video (Sep. 11, 2014) NASA captures video of a significant flare surging off the sun. Jillian Kitchener reports. Video provided by Reuters
Powered by NewsLook.com
Europe Readies 'space Plane' For Sub-Orbital Test Flight

Europe Readies 'space Plane' For Sub-Orbital Test Flight

AFP (Sep. 10, 2014) The European Space Agency on Tuesday put the final touches to its first-ever "space plane" before blasting it into sub-orbit for tests aimed at eventually paving the way to the continent's first space shuttle. Duration: 00:52 Video provided by AFP
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:
from the past week

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