Author Archives: Allen Versfeld

About Allen Versfeld

Allen is an amateur astronomer, an IT professional, a podcaster, a father of five growing kids, a barely competent chess player, and the owner and publisher of the Urban Astronomer podcast and website. He has formerly served as Director of the Astrophotography and Citizen Science sections of the Astronomical Society of South Africa. You can find his personal social media feed on Mastodon!

The planetary nebulae are aligning

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Stars are formed in loose groups called open clusters. For the first few hundred millions of years, they pull and tug on each other in chaotic orbits till, one by one, they drift away in unpredictable directions and the cluster evaporates. Although, on a grand scale, these stars all follow similar orbits around the core of the galaxy, locally their motions and orientations are in all directions. So when astronomers from the university of Manchester conducted a study looking at … Continue reading →

What is a planetary nebula?

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Planetary nebulae are clouds of dust and gas ejected from older stars as they move on to the next stage in their evolution. When a star uses up all its hydrogen fuel, and begins to burn helium, the core heats dramatically, causing the outer layers of the star to inflate dramatically. The outer layers of the star escape its gravity, and the solar wind of high energy particles and radiation accelerates the still superheated plasma out into space where it … Continue reading →

The Dark Energy Survey

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On August 31, a team of scientists working on the Dark Energy Survey (DES) turned on the world’s most powerful digital camera and pointed it upwards, beginning the process of systematically imaging the entire sky. The resulting imagery will be assembled into the most detailed map of the Universe every created, so that cosmologists can begin picking away at the problem of Dark Energy to answer that most troubling of questions in astronomy: Why is the expansion of the universe … Continue reading →

Milky Way’s Black Hole a Picky Eater

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If there’s one thing nearly everybody knows about a black hole, it’s that they voraciously gobble up anything and everything that drifts nearby. It’s not true, of course, since they’re powered by nothing more mysterious than gravity, so plenty material falling inwards manages to miss the black hole and gets sling-shotted back into space. But even so, astronomers studying Sgr A* (the supermassive black hole at the centre of the Milky Way Galaxy) were surprised to notice that less than … Continue reading →

Carnival of Space #335

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Welcome to the second week of 2014, where Brian Wang of Next Big Future presents the 335th Carnival of Space. Every week, astronomy and space science bloggers from round world submit samples of their best writing to the carnival editor, who compiles them into a weekly list of news and updates for the Carnival of Space. This week isn’t a huge one, so you’ll have time to read the articles extra carefully. First up is Universe Today with their article … Continue reading →