ESO Top 10 Astronomical Discoveries
- Stars orbiting the Milky Way black hole
Several of ESO's flagship telescopes were used in a 16-year long study to obtain the most detailed view ever of the surroundings of the monster lurking at the heart of our galaxy — a supermassive black hole.
Schödel et al. 2003 (Telbib),
Gillessen et al. 2009 (Telbib)
Read more in the ESO Press Release eso0226, eso0846 and eso1151. The Crafoord Prize in Astronomy 2012 was awarded for this result.
- Accelerating Universe
Two independent research teams, based on observations of exploding stars, including those from ESO's telescopes at La Silla and Paranal, have shown that the expansion of the Universe is accelerating. The 2011 Nobel Prize in Physics was awarded for this result.
Perlmutter et al., 1999ApJ...517..565P (Telbib),
Riess,A. et.al., 1998, AJ116 1009 (Telbib),
Schmidt, B. et.al., 1998, ApJ 507 46 (Telbib),
Perlmutter, S. et al, 1998, Nature, vol. 391, 51 (Telbib),
Tonry, J.L. et al, 2003, ApJ (Telbib),
Knop, R.A. et al, 2003, ApJ (Telbib),
Riess, A. et al, 2004, ApJ (Telbib),
Astier, P. et al, 2006, A&A (Telbib)
Read more in the ESO Press Release eso9861
- First image of an exoplanet
The VLT has obtained the first-ever image of a planet outside our Solar System. The 5-Jupiter-mass planet orbits a failed star — a brown dwarf — at a distance of 55 times the mean Earth-Sun distance.
Chauvin et al. 2004 (Telbib)
Read more in the ESO Press Release eso0428
- Gamma-ray bursts – the connections with supernovae and merging neutron stars
ESO telescopes have provided definitive proof that long gamma-ray bursts are linked with the ultimate explosion of massive stars, solving a long-time puzzle. In addition a telescope at La Silla was able for the first time to observe the visible light from a short gamma-ray burst, showing that this family of objects most likely originate from the violent collision of two merging neutron stars.
Galama T.J., et al., 1998, Nature
Hjort et al., 2003 (Telbib)
Hjorth, J., et al., 2005, Nature
Pian, E., et al., 2006, Nature
Read more in the ESO Press Release eso0318 and in the ESO Press Release eso0533
- Cosmic temperature independently measured
The VLT has detected carbon monoxide molecules in a galaxy located almost 11 billion light-years away for the first time, a feat that had remained elusive for 25 years. This has allowed astronomers to obtain the most precise measurement of the cosmic temperature at such a remote epoch.
Srianand, R. et al, 2008, A&A (Telbib)
Noterdaeme et al., A&A (Telbib)
Read more in the ESO Press Release eso0813
- Oldest star known in the Milky Way
Using ESO's VLT, astronomers have measured the age of the oldest star known in our galaxy, the Milky Way. At 13.2 billion years old, the star was born in the earliest era of star formation in the Universe. Uranium has also been detected in a Milky Way star and used as an independent estimate of the age of the galaxy.
Pasquini et al. 2004 (Telbib)
Cayrel, R et al, 2001, Nature
Read more in the ESO Press Release eso0425 and in the ESO Press Release eso0106
- Flares from the supermassive black hole at the centre of the Milky Way
The VLT and APEX team up to study the violent flares from the supermassive black hole at the centre of the Milky Way, revealing material being stretched out as it orbits in the intense gravity close to the central black hole. In addition exquisite VLT observations revealed powerful infrared flares coming from the black hole, strongly suggesting that it rotates very rapidly.
Eckart, A. et al, 2008, A&A
Eisenhauer, F. et al, 2005, ApJ
Read more in the ESO Press Release eso0841
- Direct measurements of the spectra of exoplanets and their atmospheres
The atmosphere around a super-Earth exoplanet has been analysed for the first time using the VLT. The planet, which is known as GJ 1214b, was studied as it passed in front of its parent star and some of the starlight passed through the planet’s atmosphere. The atmosphere is either mostly water in the form of steam or is dominated by thick clouds or hazes. This follows from the earlier first direct spectrum of an exoplanet.
Bean, J. et al, 2010, Nature
Janson, M. et al, 2010, ApJ
Read more in the ESO Press Release eso1047 and in the ESO Press Release eso1002
- Richest planetary system
Astronomers using ESO’s HARPS have discovered a planetary system containing at least five planets, orbiting the Sun-like star HD 10180. Also evidence that two other planets may be present, one of which would have the lowest mass ever found. Furthermore, the team also found evidence that the distances of the planets from their star follow a regular pattern, as also seen in our Solar System.
Lovis, C. et al, 2010, A&A
Read more in the ESO Press Release eso1035
- Milky Way stellar motions
After more than 1,000 nights of observations at La Silla spread over 15 years, astronomers have determined the motions of more than 14,000 solar-like stars residing in the neighbourhood of the Sun, showing that our home galaxy has led a much more turbulent and chaotic life than previously assumed.
Nordström, B. et al, 2004, A&A
Read more in the ESO Press Release eso0411