In the show this time, we have an interview with Dr Dan Evans about black holes and jets and put your astronomical questions to Dr Tim O'Brien. As always we round up your feedback and bring you a selection of odds and ends from the astronomy world.
Dr Dan Evans is an astrophysicist at MIT's Kavli Institute for Astrophysics and Space Research and also holds a research affiliation with Harvard University, at the Harvard-Smithsonian Center for Astrophysics. In this interview he talks about his main research interests of X-ray and multiwavelength observations of phenomena related to supermassive black holes in Active Galactic Nuclei (AGN). He can also be found on the History Channel's 'The Universe' TV series.
Ask an Astronomer
Libby Jones puts your astronomical questions to Dr Tim O'Brien:
- Our first question is from Carol. She emailed in to ask "What passed through the sky at 8.51pm last night? Details were on the local news/weather but we missed the name etc. We were really excited at seeing this but have been unable to find out what it actually was. Hope you can help."
- Heavens Above - find details of visible passes of ISS and other satellites.
- @twisst - follow ISS on Twitter.
- Over Twitter - @orbitingfrog's list of feeds like @overmanchester.
- @jodrellbank on Twitter.
- We had an enquiry from Philip Le Riche. He says "The Perseids, we are told, are the dust left behind by Comet Swift-Tuttle along its orbit around the Sun. Most of this dust (according to Wikipedia) is around 1000 years old. This puzzled me as I was watching out for them the other week. The dust certainly won't be left along the length of its orbit like an explorer carrying a leaky bag of flour in order to mark his path through a forest. In fact, the dust will be blown further and further away from the orbit by the solar wind and radiation pressure, eventually contributing to the zodiacal light, and it's hard to see how any of it could end up at the diametrically opposite end of the comet's 130 year orbit. So how is it that the Perseids can be seen year after year, and not just around the time Swift-Tuttle crosses the earth's orbit?"
- The International Meteor Organisation aims to encourage, support and coordinate meteor observing, to improve the quality of amateur observations, to disseminate observations and results to other amateurs and professionals and to make global analyses of observations received world-wide.
- Meteorwatch used Twitter to discuss the Perseid meteor shower.
- Calculations of the Leonid meteor shower from the Armagh Observatory group.
- The next question is from Nick Beer. He wrote in to say "I gather the Universe started from a singularity at the Big Bang and has been expanding ever since. If so, in what direction relative to our Galaxy is that singularity, what is happening there, what is between it and ourselves, is matter still being created there and how far from it have we travelled in 13.5bn years? When I hear that the Universe is receding from us in all directions, and the further away the galaxies are from us, the faster they are receding, I get the impression that we are considered the centre of the universe. I hope these questions do not appear too silly; I would love to have your views. (I adore the show, by the way!)."
- Always a useful read: Ned Wright's FAQ in Cosmology.
- Recipe for currant cake - to use this as an analogue for the expanding universe you may need to adjust the amounts of ingredients!
- Next we have another cosmological question from Russ Jenkins: "If I understand correctly we are not able to give an estimate of the real size of the universe, only an estimate of the furthest object it will ever be possible to see, given the age of the universe, the speed of light and a bit of adjustment for inflation. But we do have models of the Big Bang going right back to microseconds after the event. So surely we think we know what size it was then, also its total mass and total energy content. At what point do we lose track and stop being able to even estimate these things?"
- Ned Wright's History of the Universe.
- Our final question for this month is from Ankit who writes "Dear sir, I have opted to study the electronics and communication branch of engineering (ECE). Can you please tell me whether it has any scope in astronomy. How can I then build my career in astronomy after engineering?"
Odds and Ends
We are having a Jodcast meetup (JodPub) on Saturday 25 September 2010. The Jodcast team will be in Kro 2 in Manchester from 4.30pm and we would love to meet you all.
The story of Hanny's Voorwerp has been made into a comic! It is available to buy or you can read it online for free.
The winners of the 2010 Astronomy Photographer of the Year competition have been announced. An exhibition of the winning entries will be at the Royal Greenwich Observatory until February 2011.
"How not to be afraid of the dark" a performance combining astronomy and poetry will be at Thinktank in Birmingham on September 23rd and the Greenwich Observatory on November 29th.
The LOFAR-UK team have made a video tour of the site in Chilbolton.
|Interview:||Dr Dan Evans and David Ault|
|Ask An Astronomer:||Dr Tim O'Brien and Libby Jones|
|Presenters:||David Ault and Jen Gupta|
|Editors:||Jen Gupta, David Ault and Tim O'Brien|
|Segment voice:||Lizette Ramirez|
|Website:||Stuart Lowe and Jen Gupta|
|Cover art:||A composite image of NGC 1068, one of the nearest and brightest galaxies containing a rapidly growing supermassive black hole. X-ray data from the Chandra X-ray Observatory are shown in red, optical data from the Hubble Space Telescope in green and radio data from the Very Large Array in blue. Credit: NASA/CXC/MIT/C.Canizares/D.Evans et al/STScI/NSF/NRAO/VLA|