Your Night Sky for Sept. 25, 2019

Bright Formalhaut

Bright Formalhaut
This is the time of year to look for the bright star Formalhaut in the south about one-third of the way up. It’s part of the faint constellation Piscis Austrinus the Southern fish and marks its mouth. Because this is such a faint constellation, it isn’t visible without a telescope.

That’s why Formalhaut is known as the Loneliest Star because there are no other bright stars anywhere near it. It’s basically a southern hemisphere star, so we can only see it in the fall. But it is the 18th brightest star in our sky.

In 2008 it was found to have a planet and the Hubble Space Telescope photographed it in 2012. The planets name is Dagon, and it’s estimated to have a 2,000 year highly elliptical orbit. The only way astronomers found Dagon was to block Formalhaut’s light so they could see things around it. They found rings, fuzzy rings of dust, and the planet. This was actually the first planet officially to be seen orbiting a star.

Formalhaut is considerably hotter and heavier than our Sun. If they were side by side, Formalhaut would outshine our Sun by around 17 times. Since its 25 LY from us, we can’t really see how big and bright it is. In 2013 it was found to be a triple star. The other 2 stars are not visible to us, but Formalhaut twinkles blue, white and green which we may be able to see since it’s very bright and easy to find. Just look in the south to the left of the Milky Way and Saturn. Since the New Moon is on Sept. 28, the sky will be great to observe.

The Planetary Society, which I have been a member of for a long time, recently launched the Light Sale 2. This space craft is controlling its orbit solely by the power of sunlight. This is amazing because it’s building its orbital altitude by hundreds of meters every day. It’s the first small space craft propelled by sunlight, and this is an amazing idea for future spacecraft. It’s an extension of using sunlight for home power.