Armchair astronomy - catch a supernova from home?
20 January 2000Once upon a time astronomers were passionate star-lovers who were eagerto climb up a mountain just to get the clearest view of the night sky.Not anymore. It seems that the climbing - though not the passion -can now be avoided. On 12 January a supernova explosion was discovered byan Italian amateur astronomer who was operating a telescope from his homecomputer, via the Internet. And it is not the first time it has happened: the samegroup found another supernova in the same way just before Christmas. "Of coursewe are very excited about these findings!", says Alessandro Dimai, one of the happy discoverers.
These findings signal the arrival of new ways to do astronomical research. With remote-controlled telescopes experts envisage a more efficient use of the instruments, more collaborations among scientists and a more even and fair distribution of knowledge. "For decades we've been learning about remote control of telescopes in the space missions. Ground-based observatories are now actively trying to implement it, and astronomers will certainly benefit from it", says ESA engineer Daniel Ponz, based at ESA's Villafranca station in Madrid, who is involved in a project to develop these techniques.
At 05.30 on the morning of 17 December, Dimai, a member of the Italian association 'Associazione Astronomica Cortina', was unable to sleep. As usual he sat at his computer and got connected with the Osservatorio Astronomico del Col Druscih, at 1 785 metres altitude, and 10 kilometres away from his home. The 0.5 metre telescope in the observatory is currently the only automatised, remotely-accesible telescope in Europe: its users can open its dome, point the telescope and get and archive the image from home.
Dimai took about twenty images before sunrise and reviewed them quickly. He realised that in one of the galaxies, the spiral M61, there was a little star that was missing in other pictures of the object. "We have been observing galaxies for years, searching for supernovae. We are used to doing it", says Dimai to explain how was able to identify the new bright point among all the others in M61.
The astronomer had to react quickly to his discovery. A supernova is the violent death of a massive star, which has consumed all the 'fuel' in the nuclear reactions that make it shine and is therefore unable to produce energy any longer: as a result, it collapses under its own gravity and explodes so violently that for days its brightness outshines that of the galaxy. The sooner scientists can observe the phenomena, the more data they will get about it. Dimai immediately warned several observers all over the world via the Internet and in less than 24 hours the California University confirmed his suspicions: the little new star was indeed a supernova. The discovery was formally announced by the International Astronomical Union (IAU), which last year recognized 200 supernovae.
The latest, brightest and farthest
The story was repeated again a few nights ago, on 12 January, with amateur astronomer Marco Migliardi as the discoverer. 'His' supernova is one of the firsts of the year 2000, and the IAU has catalogued it as "sn2000C". It is brighter than the one in M61, although it is farther away: 300 million light-years away in the Lynx constellation - Dimai's supernova was 60 million light-years away in the constellation of Virgo.
These two supernovae are the first ever discovered with a remote-controlled telescope. The Col Druscie telescope can be operated in this way thanks to a system implemented by engineer Sergio Pascolini (alefpgtin.it), which allows its users simply to ask observing time by e-mail. Dimai, a 38 year-old bank employee by day, says that "the programme is very easy to use. It allows us to do more observations and hence the probability of making a discovery is higher".
Ponz shares his views. "Remote observations is at present a very active area of research also in professional observatories. It will bring an important change in the way we do astronomy, bringing the telescopes closer to the community".
Last August he collaborated in an experiment to control a professional telescope, the NOT, in the Observatorio del Roque de los Muchachos in the island of La Palma (Canary Islands, Spain), from ESA's Villafranca station in Madrid. The test, pioneered in Europe and in the frame of a project called 'Dynacore' (funded by the European Commission), started with observations directed by astronomers in Madrid - from the Laboratorio de Astronomma Espacial y Fmsica Fundamental at the ESA's station; control then went to a group in the Osservatorio di Trieste (Italy), ending up in the Lund Observatory (Sweden).
"We are changing the classical and romantic image of the astronomer isolated on top of a mountain, searching through the sky", Ponz says. "But that unique experience, in my opinion, is very similar to what we felt when we saw the Ring Nebula obtained by the NOT telescope that we were controlling from Villafranca".
For more information:
- Associazione Astronomica Cortina