Twitter Facebook Flickr YouTube

November 2018: Fixers

November 2018

In the show this time, we talk to Richard Bower about simulating the Universe with the EAGLE project, Shruti Badole rounds up the latest news, and we find out what we can see in the November night sky from Ian Morison and Haritina Mogosanu.

The News

This month in the news: the slowest-spinning pulsar ever discovered, elusive dust clouds around the Earth finally detected and the Hubble Space Telescope returns.

First up in the news: An international team of astronomers led by Chia Min Tan, a doctoral student at our very own Jodrell Bank Centre for Astrophysics, has discovered the slowest-spinning pulsar ever. The team also comprised of astronomers at the Netherlands Institute for Radio Astronomy, also known as ASTRON and the University of Amsterdam.

Pulsars are rapidly spinning neutron stars, which are basically the collapsed cores of massive stars that have undergone supernova explosion. They are extremely dense and are also highly magnetised, as a result of which, the spinning of the neutron star leads to generation of electromagnetic radiation. This radiation manifests itself in the form of beams emanating from the magnetic poles of the pulsars. Similar to a lighthouse, the beams from a pulsar flash consistently and can only be observed if the radio emission from the beam is facing the Earth. While the fastest spinning pulsar ever discovered rotates once every 1.4 milliseconds, meaning 716 times per second, the slowest pulsar known until this discovery rotates every 8.5 seconds. This record has now been broken by the recently discovered radio pulsar PSR J0250+5854, whose rotation period has been found to be 23.5 seconds. The pulsar is approximately 14 million years old and is located in the constellation Cassiopeia, around 5,200 light years away from the Earth. It was discovered as part of the LOFAR Tied-Array All-Sky Survey that is searching for pulsars in the Northern sky.

Generally, pulsars are said to have reached their "death line" after about 10 to 100 million years, when the magnetic mechanism responsible for the pulsar jets shuts down. The newly discovered pulsar is considered to be very unusual because it goes beyond the conventional pulsar death line, where the radio emission is expected to cease. A co-author of the study, Dr Jason Hessels from ASTRON and the University of Amsterdam, says: "This discovery was completely unexpected. We're still a bit shocked that a pulsar can spin so slowly and still create radio pulses. Apparently radio pulsars can be slower than we expected. This challenges and informs our theories for how pulsars shine."

The team plans to further study the pulsar with the European Space Agency's XMM-Newton space telescope. Chia Min Tan says, "This telescope is designed to detect X-rays. If the super-slow pulsar is detected as a source of X-rays, then this will give important insights into its history and origin". Meanwhile, the team is looking forward to discovering more pulsars with the LOFAR survey. The study can be found in the Astrophysical Journal.

In other news: A team of astronomers from Hungary have confirmed the existence of two clouds of dust at gravitationally semi-stable points about 400,000 kilometers from the Earth. The possibility of the existence of these clouds, known as Kordylewski dust clouds (or KDCs), was first discussed by the Polish astronomer Kordylewski in 1961. However, due to their extreme faintness, KDCs remained elusive objects and their existence was doubted by a lot of astronomers all these years. In the new study, the team of astronomers modeled KDCs to understand their formation and detection. The results obtained are consistent with the earliest observations of KDCs made over six decades ago and also match with predictions made by an earlier research by the team. Team member Dr. Judit Sliz-Balogh of the Eotvos Lorand University commented on the discovery, saying: "KDCs are two of the toughest objects to find, and though they are as close to Earth as the Moon are largely overlooked by researchers in astronomy. It is intriguing to confirm that our planet has dusty pseudo-satellites in orbit alongside our lunar neighbor". Two research papers related to the study can be found in the Monthly Notices of the Royal Astronomical Society.

And finally: The Hubble Space Telescope is back in action! The HST, that has 6 gyroscopes that help maintain its orientation during observations, faced a glitch early October after failure of one of the gyroscopes. There was further trouble with the backup gyroscope as well, which was spotted after the rotation rates it measured were found to be higher than the actual ones. This sent the HST into a protective safe mode, putting all science observations on hold. Thankfully, after a series of engineering tests undertaken by the Hubble operating team, the telescope has now returned to normal science operations.

Interview with Richard Bower

Professor Richard Bower (University of Durham) talks to us about theoretical and observational aspects of studying galaxies and galaxy clusters. As part of the EAGLE project he has simulated the Universe, and tells us how they went about such a monumental task plus what they've learnt from it. He also updates us on the Ordered Universe project, a conjunction of science, history, and language in the study of Medieval scientific literature.

The Night Sky

Northern Hemisphere

Ian Morison tells us what we can see in the Northern Hemisphere night sky during November 2018.

The Planets

Southern Hemisphere

Haritina Mogosanu from the Carter Science Centre in New Zealand speaks about the Southern Hemisphere night sky during November 2018.

Odds and Ends

Recently published ALMA observations of Europa at millimetre wavelengths include maps of Europa that show details as small as 200 km. While this is a technically impressive imaging achievement, the results can also be used to understand the composition of the surface of Europa as well as the thermal characteristics of the moon. Pictures and more information are available from the press release.

The Opportunity Rover on Mars, which has been sending data back to Earth for fourteen years, has fallen silent since 10th June 2018, when a severe dust storm made it unable to use its solar panels to generate power. On 11th September, NASA announced that they would undergo a 45-day "active listening" period, where they'd both attempt to send commands to Opportunity and listen for any signals arriving from it. The initial 45-day deadline has now passed, but NASA has decided to extend their attempts to contact Opportunity until January 2019, as over the next few months the area Opportunity was in will see strong winds. It's hoped that if Opportunity's silence is because its solar panels are covered in dust, these winds might clear it off and allow us to communicate again. If you're interested in updates on this, Twitter hashtags #WakeUpOppy and #SaveOppy will let you follow any news.

Are you feeling lucky? The authors of a new study on O-type stars are, having extended the technique of lucky imaging to work with a spectrograph, pioneering "lucky spectroscopy". Taking many spectra with very short exposure times, the effects of atmospheric turbulence are mitigated, which has allowed the blended components of five O-star systems to be resolved, some for the first time.

Show Credits

News:Shruti Badole
Interview:Richard Bower and Emma Alexander
Night sky:Ian Morison and Haritina Mogosanu
Presenters:George Bendo, Fiona Porter and Jake Staberg Morgan
Editors:George Bendo, Beth Jones, Tom Scragg, Hongming Tang and Bin Yu
Segment Voice:Tess Jaffe
Website:Jake Staberg Morgan and Stuart Lowe
Producer:Jake Staberg Morgan
Cover art:A new ALMA image of the Galilean moon Europa. CREDIT: ALMA (ESO/NAOJ/NRAO), S. Trumbo et al

Download Options

Subscribe (It's free)