It’s out there

By Michael Banks in Miami, Florida

We need to better understand how other stars behave before we start looking for planets orbiting around them. That was the message from astronomers speaking in a session on searching for exoplanets at the 216th American Astronomical Society meeting in Miami, Florida.

Annie Baglin from the Observatoire de Paris, France, spoke about the $160m Convection Rotation and Planetary Transits (CoRoT) mission, built by the French Space Agency, which launched in 2006.

CoRoT has two objectives: to study the solar variation in other stars as well as searching for exoplanets via a technique known as “transiting”, where a planet passing in front of the star causes its solar output as seen by the satellite to dim slightly.

Indeed, CoRoT has already had breakthroughs in studying solar variations in other stars including hot stars and red giants. Yet the science that gets the most attention is CoRoT’s search for exoplanets.

Although CoRoT lost the use of two of its detectors last year, the craft is still going strong and has managed to detect a range of exoplanets.

Most of the exoplanets spotted by CoRoT are big, hot planets such as CoRoT-3b, which has a mass 21 times that of Jupiter.

On 17 March CoRoT discovered CoRoT-9b, which has a radius similar to Jupiter and a temperature of 350 K. “If it has moons, then they would be habitable,” says Baglin. But getting to the planet is another matter as it is lies 1500 light-years away.

The biggest find to date is possibly CoRoT-7b, discovered in February 2009, which has a similar diameter and mass to Earth.

Baglin outlined in her talk how difficult it is to spot such small planets saying that constant changes in the star’s activity makes it very difficult to detect planets orbiting them. “Once we have a better understanding of a star’s cycle then we will be better placed to start to look for exoplanets,” says Baglin.

CoRoT still has another three years to run, but it has already been superseded somewhat by NASA’s Kepler mission, which launched in March 2009 to look for Earth-like planets. “Kepler will do more than what we have,” says Baglin.

By Michael Banks in Miami, Florida

The common view of black holes residing at the centre of their host galaxies might not be completely true, according to astronomer Daniel Bacheldof, from the Florida Institute of Technology.

Speaking today at the 216th American Astronomical Meeting in Miami, Florida, Bacheldof and colleagues used old data taken from the Hubble Space Telescope to show that the supermassive black hole at the centre of the M87 galaxy is slightly displaced from its centre.

The fact that a supermassive black hole – black holes that are millions or billions time the mass of the Sun – can be displaced from the centre of a galaxy is not new, but the fact that astronomers have spotted such a small displacement means that small off-sets could be more common than previously thought.

The explanation for the displacement comes from the fact that the supermassive black hole in M87 was a merger between two smaller black holes. When they merged, the emission of gravitational waves “kicked” the newly created black hole, knocking it slightly off-centre. “What we are seeing in M87 is in effect indirect evidence for gravitational waves,” notes Bacheldof.

The fact that many other supermassive black holes show similar properties to M87 could indicate that such off-sets are common in the universe. “No longer can it be assumed that all supermassive black holes reside at the centres of their host galaxies,” says Bacheldof, who is looking at other such systems to spot similar effects. Time to re-write those astronomy textbooks?

Exhibitors at the 216th American Astronomical Meeting

By Michael Banks in Miami, Florida

Walking into the exhibition hall at the 216th American Astronomical Meeting in Miami, Florida, it seems like this year’s must-have is a TV screen.

That is, of course, to show all the awe-inspiring images and movies that their missions are just releasing, be it from the Herschel mission, the Wide-field Infra-red Survey Explorer or the Solar Dynamics Observatory (SDO).

My favourite is the SDO booth and not just because of the free 3D glasses, but because of the quality of the images that the mission has just started to release (though they did give me a nice coaster).

The SDO booth also has two TV screens, obviously one is not enough.

With the enticement of tortilla chips, I also caught some of the poster session, which did not seem overly subscribed. Maybe people were instead enjoying the Miami sun outside.

Bono was due to grace the iconic Pyramid Stage. Credit: James Dacey

By James Dacey

The colossal Irish rock group U2 broke thousands of hearts this morning when they announced that they can no longer play their headlining slot at this year’s Glastonbury festival, a result of Bono putting his back out during rehearsals last week. The big question now is – who will replace them?

Well, if festival organizer Michael Eavis is willing to put reputations aside and choose a replacement purely on their musical similarity to U2, he may enlist the help of physicists in Brazil.

Luciano da Costa at the University of Sao Paulo and her colleagues have developed a new way of grouping music based on the subtle differences in rhythm between musical genres.

The researchers studied four musical genres – rock, blues, bossa nova and reggae – looking at 100 songs from each category, analysing the most representative sequences of each rhythm.

They then represent the rhythms as a Markov chain where the nature of each beat depends only on the preceding beat. “Basically, this means that we consider the time duration of each of two subsequent notes in order to obtain the probability transition between each type of notes (duration) in each given composition,” explains Costa.

Costa and her co-author Debora Correa are both classical pianists and they say that this has been an influence on their work. “We wanted to investigate how computing, maths and physics could be used to help us characterize and understand music and music genres,” says Costa.

So okay, I think we can be fairly certain that Michal Eavis will not involve Markov chains in selecting his U2 replacement, but this research could potentially have a far wider impact in the music industry. The researchers believe it could help to improve music platforms, such as Apple’s iTunes, which can group music to make recommendations based on the kind of music you regularly play.

You can read about the method in this open-access paper published recently in New Journal of Physics.

Does what it says on the mouse mat

By Michael Banks in Miami, Florida

I was wondering how long it would be before I heard Will Smith’s 1998 hit song “Miami”, but I didn’t expect it while walking into a session at the 216th American Astronomical Society meeting.

This evening I attended a special symposium on the status of the Atacama Large Millimeter/submilliter Array (ALMA, which is currently being constructed in the Atacama desert in Chile.

Built by the European Southern Observatory and the US National Radio Astronomy Observatory (NRAO), when fully complete in 2013, ALMA will contain 66 antennas in total and be 100 times more sensitive than other millimetre telescopes.

ALMA will allow astronomers to study a range of phenomena including planetary and star formation.

There are currently four antennas up and working, with another 12 planned before ALMA begins science operations, which is expected to happen in early 2011.

Al Wootten, from the NRAO, who has been involved with planning ALMA for the last 20 years, says that the sensitivity together with the large bandwidth will make it a unique facility.

Speakers at the symposium were encouraging astronomers to submit ideas for using time on the telescope. “What ALMA will excel at is exploring the unexpected,” says astronomer Kelsey Johnson from the University of Virginia.

Oh, and if you are an engineer or scientist really interested in working at the ALMA telescope then they are currently recruiting and apparently want to hear from you.

By James Dacey

In his time his views may have shocked the Catholic church to its core, but on Saturday Nicolaus Copernicus was blessed and reburied by some of Poland’s highest-ranking clerics, nearly 500 years after he was laid to rest in an unmarked grave.

The ceremony came five years after what were believed to be the remains of the great astronomer were discovered beneath the floor of the cathedral in Frombork, on Poland’s Baltic coast.

Subsequent DNA analysis has confirmed the discovery after an amount of Copernicus’ hair was discovered inside a copy of his 16th century astronomy reference book Calendarium Romanum Magnum.

This short film describes Saturday’s events and how the Catholic church has tried to patch things up with the scientific community in recent years.

The heart and soul of the universe (credit: NASA/JPL-Caltech/UCLA)

By Michael Banks in Miami, Florida

It’s a hard task to walk into a session here at the 216th American Astronomical Society meeting in Miami, Florida, and not see amazing images of the universe.

But probably one of the best was issued today by researchers working on NASA’s Wide-field Infrared Survey Explorer (WISE).

Wise is an infrared telescope that was launched in December to probe the coolest stars in the universe and the structure of galaxies at four wavelengths between 3 and 25 µm.

Costing $320m, WISE circles the Earth’s poles at an altitude of 525 km scanning the entire sky one-and-a-half times in nine months.

Ned Wright, WISE’s principal investigator, said that the satellite has already taken over a million images and surveyed about three-quarters of the sky. By the beginning of November its objectives should be complete as the solid-hydrogen coolant is exhausted.

The image shows the so-called heart and soul nebula, which lies 6000 light-years away from Earth. WISE allows us to probe this star-making factory in unprecedented detail, letting us see the gas and dust that are just about to form stars.

Look this way: Dennis Matson telling us all about Titan

By Michael Banks in Miami, Florida

I was up bright and early this morning to attend the opening symposium at the 216th American Astronomical Meeting in Miami, Florida.

The talk was about Titan, the largest moon of Saturn, and was given by Dennis Matson from NASA’s Jet Propulsion Laboratory, a project scientist for the Cassini-Huygens mission that launched in 1997.

Huygens, a European Space Agency mission, was launched together with NASA’s Cassini satellite for a seven-year trip to Saturn. While Cassini travelled off to orbit Saturn, Huygens separated to head to Titan where it landed in 2004.

You might think Titan is a lifeless body orbiting Saturn, but Matson showed it to be anything but. With lakes of Methane on the north pole of the moon – some as large as Lake Superior – as well as evidence for plate tectonics, volcanoes and sand dunes forming on the surface, the moon is very much alive.

That is not all, as Matson flashed images of methane clouds and possible deposits of lava. There is even a claim that an ocean of liquid water exists underneath the rocky surface.

Even with our knowledge of Titan, there is still a lot to find out, including whether the moon has a magnetic field.

After five years on Titan, Huygens has now delivered most of its objectives so astronomers are planning what the next mission could be to Saturn’s sixth moon.

Matson outlined two possible missions astronomers are looking into. One is using a probe attached to a balloon that would circumnavigate the moon at an altitude of 10 km. This would allow scientists to get a global picture of the moon closer to its surface.

The other possible mission is an 85 kg probe that would float on one of Titan’s lakes, which could, for example, probe its depth.

Astronomers probably have other ideas up their sleeves, but in the end they may be constrained by technology. “We even had some people who thought about sending some sort of submarine to Titan to explore the lake,” says Matson.