Astronomer Giovanni Sostero, 1964-2012

Giovanni Sostero, 1964-2012. Image courtesy of the Remanzacco Observatory

With sadness, we learned of the death of amateur astronomer Giovanni Sostero last Friday. Universe Today readers will remember Giovanni as a member of the team of astronomers from the Remanzacco Observatory in Italy, whose outstanding work we frequently feature, especially for their observations of comets, asteroids and supernovae. Tragically, Giovanni was just 48 years old and passed away due to complications following a heart attack.

Giovanni was credited with the discovery of several supernovae, and Asteroid 9878 Sostero (1994 FQ) was named after him to honor his astronomical observations. His work was published in several professional astronomical journals and he was a leading and active member of the Associazione Friulana di Astronomia e Meteorologia, based in Friuli, Italy, and was an honorary member of the Astronomical Observatory of Visnjan in Croatia.

Not only did he work hard behind the eyepiece, but he was very active in public outreach about astronomy.

Giovanni’s closest colleagues were his co-astronomers at the Remanzacco Observatory, Ernesto Guido and Nick Howes. Both have graciously penned their remembrances of Giovanni for Universe Today, so please read on to get a true sense of not only how much Giovanni contributed to the world of astronomy, but also his unique personality. He will be greatly missed and we at Universe Today send our condolences to his family and friends.

From Ernesto Guido

Over the past eight years, I had the privilege to undertake astronomy projects working closely with Giovanni Sostero. In fact our collaboration and friendship started at the beginning of 2005. At that time Giovanni was already an accomplished amateur astronomer known both nationally and internationally for its expertise, his scientific rigor and for his overwhelming passion for the comets. For my part, I was then moving the first steps as a young amateur astronomer. Eager to do my part, I dearly wanted to be a part of any team with the best names in contemporary astronomy and for these past 8 years was lucky enough to meet Giovanni along my own personal road.

Born in Udine in 1964, Giovanni was for many years President of the Italian astronomy association AFAM of Remanzacco. He was coordinator of the comet section of UAI (Unione Astrofili Italiani) and one of the leaders of CARA Team (Comet AfRho Research Group). He began his collaboration with the UAI Comet section in 1983 (the year of perihelion passage of 22P/Kopff), and subsequently participated to the International Halley Watch watching the 21P/Giacobini-Zinner and 1P/Halley.

His passing is a great loss for all those who loved him and for the world of astronomy. It is impossible to list here the many discoveries, articles and all contributions he made to the world of professional and amateur astronomy, not only to the field of comets.

One need only recall the 11 supernovae discovered by him in the years 2005-2009, a nova in the galaxy M31 in 2000 (the first discovery by amateur means) together with dear friends of Remanzacco Observatory, the discovery of dozens of asteroids and the observation and follow-up of hundreds of comets and Near Earth Asteroids (NEOs). In the last two years, we had embarked on a new partnership and friendship with the English amateur astronomer Nick Howes. We both agreed that we could get wonderful results together with Nick, but a cruel fate took Giovanni away too soon.

It will be impossible to fill the void he leaves, but the best way to honour him will be to continue on the road we had taken together to try shed some more light via our research on the objects he loved so much, the comets.

Giovanni was a great person, a great astronomer and the best of friends. I will miss him immensely!

Comet Garradd (C/2009 PI) as it passes by the globular cluster M92 in the constellation Hercules, was taken remotely from the Tzek Maun Observatory in New Mexico by the team of Giovanni Sostero, Ernest Guido and Nick Howes.

From Nick Howes,

I first encountered the remarkable Giovanni Sostero and his long time friend and collaborator Ernesto Guido in 2010, after the successful imaging of Comet 103P in support of the NASA AOP program. I was using the 2m Faulkes Telescopes a lot for cometary imaging, and after we got chatting, onlline, we decided to collaborate as a team working on both the Faulkes scopes and also their own observatory in Italy for ongoing cometary research projects. His knowledge of the skies was truly staggering, as was his knowledge of comets in general. I learnt so much from working with him, a kind, generous and informative individual with a phenomenal sense of humour.

You only have to look at the over 1880 NASA ADS citations he has for his work, combined with several supernova discoveries and an asteroid named after him, to realise that not only the amateur community, of which we are all proud members, but the professional astronomical community, respected and loved this man.

The reaction on the social media sites and comet mailing lists has been universal, one of shock and deep sadness, that we have lost such a wonderful mind, and such a great person. I valued his friendship greatly, his mentoring, his help and passion for astronomy were invaluable, and words can’t express the deep sadness I think we all feel. The team at Faulkes…well we’re all in deep shock… as we had great plans for this year, with the ESA comet 67P mission project, our plans to track comet ISON and comet Panstarrs L4, but Ernesto and I will continue, and aim to honour his name with many great new discoveries.

You can read more words of condolences for Giovanni here.

Close Approach: Images and Animations of Asteroid 2011 MD

Animation of 2011 MD on Monday, June 27, 2011 at 09:30 UTC. Credit: Ernesto Guido, Nick Howes and Giovanni Sostero at the Faulkes Telescope South. Click for original larger version.


Today, Monday June 27 at about 17:00 UT, asteroid designated as 2011 MD will pass only 12,300 kilometers (7,600 miles) above the Earth’s surface. Here are some images and an animation of the asteroid’s close approach taken around 09:30 UT taken by Ernesto Guido, Nick Howes and Giovanni Sostero at the Faulkes Telescope South through a 2.0-m f/10.0 Ritchey-Chretien and a CCD. The trio of astronomers say that at the time these images were taken, the asteroid had a magnitude of about 14.5. At the moment of its close approach, 2011 MD will be bright as magnitude ~11.8.

The animation above shows the object’s movement in the sky. Each image was 20-second exposure.

See more below from Guido, Howes and Sostero.

Below is a single 20-second exposure also taken by the 2 meter telescope at Faulkes Telescope South, and just below that is another image using a RGB filter.

2011 MD on Monday, June 27, 2011 at 09:30 UTC. Credit: Ernesto Guido, Nick Howes and Giovanni Sostero at the Faulkes Telescope South
2011 MD on Monday, June 27, 2011 at 09:30 UTC with RBG filter. Credit: Ernesto Guido, Nick Howes and Giovanni Sostero at the Faulkes Telescope South.

Some early observers have suggested that 2011 MD — which is only 5-20 meters in diameter — could possibly be a piece of space junk, such as a rocket booster. However, additional observations and further calculations show that this asteroid could not have been close enough to Earth any time during the space age to have started off as a rocket booster.

Trajectory of 2011 MD from the general direction of the Sun. Credit: NASA

Thanks to Ernesto Guido, Nick Howes and Giovanni Sostero for sharing their image with Universe Today. See more of their work, as well as more information about asteroid 2011 MD at their Remanzacco Observatory website. See here for more information on the Faulkes Telescope.

Again, scientists at NASA’s Asteroid Watch program at JPL say there is no danger of the asteroid hitting Earth. “There is no chance that 2011 MD will hit Earth but scientists will use the close pass as opportunity to study it w/ radar observations,” they said on the the @AsteriodWatch Twitter feed. “Asteroid 2011 MD measures about 10 meters. Stony asteroids less than 25 m would break up in Earth’s atmosphere and not cause ground damage.”