Tuesday 5 June 2012

Venus transits the sun Bloemfontein 2004


Information: Venus transits the sun. Prof. Matie Hoffman (right) and Hannes Calitz, observer at Boyden Observatory (both from the Department of Physics, University of the Free State) are watching the transit of Venus in front of the sun closely with the “sun telescope” (20 cm Celeostat  Solar Telescope). Notice the small black circle (Venus) close to Prof. Hoffman’s cap, in front of the mammoth sun.  

Date: 8 June 2004
Time: Place: Boyden Observatory
Equipment: Nikon F3 (Film); 50mm f1.8 lens.
Technique: Negatives were scanned and image was finalised in Photoshop
Photographer: Hannes Pieterse

Transit of Venus - Bloemfontein 2004

Date: 8 June 2004
Place: Boyden Observatory
Time: 06:30 – 14:00
Equipment: Nikon F3 (Film), 600mm mirror lens; 2X Converter.
Technique: Red filter. Also without filter. ND filter was used to reduce light.Image Processing: Negatives were scanned and digital images was finalised in Photoshop
Photographer: Hannes Pieterse

Information: Transit of Venus. Nobody alive today has seen a transit of Venus in front of the sun.  The last transit was in 1882.
          Sun's disk. During a transit, Venus can be seen from Earth as a small black disk moving across the face of the Sun. The duration of such transits is usually measured in hours (the transit of 2004 lasted six hours). A transit is similar to a solar eclipse by the Moon, but, although the diameter of Venus is almost 4 times that of the Moon, Venus appears much smaller because it is much farther away from Earth. Before the space age, observations of transits of Venus helped scientists use the parallax method to calculate the distance between the Sun and the Earth.
         Transits of Venus are among the rarest of predictable astronomical phenomena and currently occur in a pattern that repeats every 243 years, with pairs of transits eight years apart separated by long gaps of 121.5 years and 105.5 years. Before 2004, the last pair of transits were in December 1874 and December 1882. The first of a pair of transits of Venus in the beginning of the 21st century took place on June 8, 2004 (see Transit of Venus, 2004) and the next will be on June 6, 2012 (see Transit of Venus, 2012). After 2012, the next transits of Venus will be in December 2117 and December 2125.
          A transit of Venus can be safely observed by taking the same precautions as when observing the partial phases of a solar eclipse. Staring at the brilliant disk of the Sun (the photosphere) with the unprotected eye can quickly cause serious and often permanent eye damage. (Wikipedia information)


Sunday 3 June 2012

Kyk na die Melkweg in verskillende golflengtes



Afrikaans

Engels


Saturday 26 May 2012

ISS - Space X, Dragon makes historic space station dock

by Staff Writers Washington (AFP) May 25, 2012

SpaceX on Friday became the first commercial outfit to send its own cargo capsule to the International Space Station, heralding the start of a new era for private spaceflight.
The berthing marked the climax of the California-based company's demonstration mission to become the first to restore US access to the space outpost after NASA retired the three-decade shuttle program last year.
With no humans on board, the Dragon capsule is delivering about a half ton of supplies and science experiments for the ISS, and aims to return a slightly larger load of gear to Earth on May 31.

More...

SA to host majority of SKA project

Source: News 24

World's Largest Radio Telescope to Be Shared by South Africa, Australia

Johannesburg - Two thirds of Square Kilometre Array (SKA) antennae technologies will be built in Africa, said Science and Technology Minister Naledi Pandor at a press conference on Friday.

Two thirds of antennae technologies will be built in Africa and a third in Australia and New Zealand, she said.

Pandor said the decision to share was unexpected but SA accepts it in the name of progress.

"This may seem like a compromise, but SA is getting the majority of the project," said  Professor Justin Jonas, SKA Africa's associate director for science and engineering.

"We should be proud!"

More,,,

Sunday 20 May 2012

Transit of Venus - 5/6 June 2012

Click to enlarge image
  What is a transit of Venus?

When Venus passes directly between earth and the sun, we see the distant planet as a small dot gliding slowly across the face of the sun.  Historically, this rare alignment is how we measured the size of our solar system.
   
When is it?

The next transit of Venus occurs June 5 or 6, 2012, depending on your location.  Observers in North America see it the evening of June 5. This will be the last transit of Venus to occur in your lifetime.
   
What should I do?

Mark your calendar.  Plan your observing location and eye safety.  Tell friends.  Download and support the ToV phone app. Enjoy the rare sight!    

Venus Transformed

VENUS TRANSFORMED: Something special is happening to Venus in the evening sky. The second planet is diving toward the sun for a much-anticipated transit on June 5-6. As Venus turns its night side toward Earth, the planet is transforming into a beautifully slender and colorful crescent:

John Chumack of Dayton, Ohio, took the picture on May 14th using a 10-inch telescope. "I was blown away by the sight of Venus," he says. "The planet was 14% illuminated, 47 arcseconds in diameter, and blazing at -4.43 magnitude."

The crescent shape of Venus is easy to see in good binoculars or small telescopes. No special observing experience is required. Just find Venus in the western sky after sunset (you can't miss it), point and look. A good tripod to hold the optics steady is recommended.

As the evening wears on and Venus sinks toward the horizon, the refractive effect of Earth's atmosphere splits the crescent into the colors of the rainbow. Kevin R. Witman of Cochranville, Pennsylvania, observed the phenomenon on May 11th: "Earth's atmospheric refraction of Venus's ample light made a beautiful image through my 10-inch telescope."

More images: from Mark Marquette of Boones Creek, Tennessee; from Philippe Vanden Doorn of Rixensart, Belgium; from Luis Argerich of Buenos Aires, Argentina; from Tomasz Gołombek of Tczew, Poland; from Francesc Pruneda of Palamós, Catalonia (Spain); from Sadegh Ghomizadeh of Tehran, Iran;

Sourc: Spaceweather

Sunday 13 May 2012

First announcement: ASSA Symposium 2012


ASSA is pleased to announce this year's symposium, which will be held from 12 to 14 October 2012 at the South African Astronomical Observatory in Cape Town.

The theme of the symposium, "Looking back, looking forward", reflects the significance of 2012. On the one hand, organised amateur astronomy turns 100 this year, which will be duly celebrated at the symposium. On the other hand, hopefully by October a decision on the Square Kilometre Array will have been made. So the symposium focusses on past and future of astronomy alike.

Participants of the symposium will have the opportunity to engage in some outreach activities on 12 October. The symposium itself will start officially with a welcome evening on that day. Talks and workshops will take place throughout 13 and 14 October. In the evening of 13 October there will be a special Open Night commemorating 100 years of amateur astronomy in Southern Africa.

Online registration will be possible from 1 June, but you may submit abstracts for proposed talks before that by sending an email to symposium2012@assa.saao.ac.za. Both amateur and professional astronomers are invited to give talks. And because of the theme of the symposium, talks concerning the history of astronomy, the SKA project and science with the Southern African Large Telescope are encouraged. The submission of topics for the workshops is also very welcome.

The symposium website is at http://assa.saao.ac.za/symposium2012, and any queries about the symposium should be addressed to symposium2012@assa.saao.ac.za.

The organisers of the ASSA Symposium 2012 are looking forward to welcoming you in Cape Town!