Just in Time. In a special 10th birthday episode of the Jodcast, Professor John Seiradakis talks to us about the Antikythera Mechanism, Dr. Jean-Francois Robitaille describes the intricacies involved with measuring galactic magnetic fields, and your astronomical questions are answered by Dr. Joe Zuntz in Ask an Astronomer.
JodBite with Dr. Jean-Francois Robitaille
Dr. Jean-Francois Robitaille is a postdocoral researcher at Jodrell Bank Observatory working with Dr. Anna Scaife. Jean-Francois’ research interests are in multi scale analysis of magnetic fields in the galactic plane. In this Jodbite, he sits down with Therese to discuss these magnetic fields and how astronomers can observe them. He also describes the techniques he’s developing to understand our galaxies magnetic field in greater detail.
Interview with Professor John Seiradakis
Professor John Seiradakis is the Director of the Laboratory of Astronomy at Aristotle University, Greece. Between the years of 1971-1975 he worked towards his PhD at Jodrell Bank, alongside some voices who will be very familiar to Jodcast listeners! His many topics of research include neutron stars, flare stars and the Galactic center, and he also is also a prominent figure in the field of archeoastronomy. In this episode, John talks to us about an object he has been studying for many years: the Antikythera Mechanism. Discovered by sponge divers in the wreckage of a ship near the Greek Island of Antikythera in the Aegean Sea in 1901, the Antikythera Mechanism is an astronomical computer created during the Hellenistic Period almost 2000 years ago. It is capable of calculating the positions of the Sun and Moon, forecasting solar and lunar eclipses, and predicting the times of the Olympic Games; but our knowledge of the object is by no means complete, and the Antikythera Mechanism continues to surprise at every turn.
Ask an Astronomer
Dr Joe Zuntz answers your astronomical questions:
- Kenny Macleod asks us about cosmological redshift and what properties of the universe it affects
- Martin wants to know about the speed at which the unverse can expand and how could spacetime have behaved close to the Big Bang
- Philip King asks, "Can a gravitational lens reveal an object at different distances and times?"
Odds and Ends
Astronomers at the Max Planck Insitiute for Astronomy have developed new tools to determine the age of red giant stars from its spectrum. These tools have been applied to data from the APOGEE Survey and NASA's Kepler Space telescope, giving estimates of the ages of nearly 100,000 stars, which allowed the MPIA team, lead by astronomers Melissa Ness and Marie Martig, to create an age map of our Galaxy. Such a map has allowed the astronomers involved to put to the test theories on the formation and evolution of the Milky Way. One such theoretical prediction is that the stellar disk of the Galaxy should have formed starting at the inside (near the GC) and moving out toward the edge. This age map confirms this predictions.
An Australian-US team have discovered a gas cloud with a chemical signature that could indicate that it was enriched by the very first generation of stars, known as population III stars. The gas that formed after the Big Bang contained mostly hydrogen and some helium, with a tiny fraction of slightly heavier elements. Gas clouds in galaxies today contain a far higher percentage of heavier elements, much of which have been created in several generations of successively more chemically interesting stars, and in supernova explosions when massive stars reach the end of their lives; this kind of chemical pollution of the interstellar medium is known as enrichment. This particular gas cloud, seen in absorption against a distant background quasar, shows a chemical fingerprint that could be explained by enrichment by just the first generation of stars. If this is the case, studying its chemical make-up could help us better understand this first generation of stars, a population which is very difficult to study any other way.
On 15th December 2015 Tim Peak became the first British ESA astronaut to set foot in the International Space Station, and will be a crew member for six months during his mission, named 'Principia'. After a first meal in space of a cup of tea and a bacon sarnie, he proceeded to phone home and speak to his answerphone, prank call a grandmother, and learn he was to be replaced at his family christmas dinner by a cardboard cutout named 'Flat Tim'. His antics will continue with a spacewalk on January 15th to replace a malfunctioning voltage regulator, and space-marathon in April 2016!
Images from the Chandra X-ray Observatory for NGC 5195, the smaller spheroidal galaxy in M51, show detailed activity related to the active galactic nucleus (AGN) in the centre of the galaxy. The AGN produces a substantial amount of X-ray emission, which is fairly typical for many AGN, but what is surprising is that the telescope also detected a pair of bow shocks south of the AGN. These bow shocks look like they were produced in outbursts occurring about 1-3 million and 3-6 million years ago. More details on the outbursts is given in the press release.
Our 10th birthday celebrations will be extending all the way through January, February and almost into March, as we're hard at work putting together a live Jodcast episode for you all. It will be at Jodrell Bank Observatory on February 28th, but to come along you'll need a ticket! Click here to apply!
Join in with a Pulsar Hunt!
We are slap-bang in the middle of BBC's annual stargazing live program (January 12th - 14th) and as with previous years they're doing a citizen science project: searching for pulsars! Some of the Jodcast team are heavily involved and you can help out too! Simply visit the website to join in the search, and follow the Pulsar Hunters for regular updates!
|JodBite:||Dr. Jean-Francois Robitaille and Therese Cantwell|
|Interview:||Professor John Seiradakis and Charlie Walker|
|Ask An Astronomer:||Dr Joe Zuntz and Hannah Stacey|
|Presenters:||Megan Argo, Adam Avison, George Bendo and Charlie Walker|
|Editors:||Benjamin Shaw and Charlie Walker|
|Segment Voice:||Kerry Hebden|
|Website:||Charlie Walker and Stuart Lowe|
|Cover art:||The Antikythera Mechanism. CREDIT: Wikimedia Commons|