Welcome to the Dark Side of Astronomy with Dave Gault, 6:30pm Monday 2 March

Presented via Zoom by David Gault

Most astronomical observations examine the light from an object. An occultation observation examines the absence of light. Imagine an observer and their telescope, safe in their backyard, in Sydney, on Planet Earth, spinning and orbiting the Sun. Imagine a star, but not just any star, tonight this one is special. It’s like all the other stars - a humongous ball of nuclear fusion, safe at a distance that boggles the mind, but tonight it’s the Target Star. Now, imagine an asteroid safe in it’s orbit around the Sun, it’s too faint to be see, but the observer is armed with the knowledge that in a few minutes time, the asteroid might, just might, hide the humongous star for a second or two, thereby measuring the diameter or chord across the asteroid.

The goal of this talk is to introduce and explain occultation observations and provide information to, perhaps wet the appetite of Sydney City Skywatchers in the hope that one or two join the Sydney Occultation Team and become a productive 'Occultation Observers'.

Left: Dave Gault with his 12inch LX200 and the crescent Moon.

Dave Gault bio

Dave is an Occultation Observer based in the Blue Mountains. He built, owns and operates Kuriwa Observatory, a small roll-off-roof backyard observatory that specialises in lunar, asteroid, and planetary moon occultation observations for the Trans-Tasman Occultation Alliance (TTOA), and the world-wide International Occultation Timing Association (IOTA).

When not observing or processing his own observations, Dave collects, collates and processes all observations made in the TTOA region (Australia and New Zealand) and he reviews observations made by observers all over the world.

Dave has authored several papers published in the Minor Planet Bulletin and Journal of Double Star Observations, and is a co-author of several papers published in Astronomical Society of Australia (PASA), The Astronomical Journal, Monthly Notices of the Royal Astronomical Society and Nature.

Asteroid (33748) Davegault has been named by the IAU in his honour.

Details: This presentation will be on-line by Zoom. Members will be emailed the Zoom link. If you are not a member and want to attend this talk please email our secretary on: sydneycityskywatchers@gmail.com.

Please log-in by 6:25pm. Notices and a short presentation by members are delivered before or after the keynote depending on circumstances.