X-raying the beating heart of a newborn star03 Jul 2012
An international team of scientists has used the world's most powerful X-ray observatories - including ESA's XMM-Newton orbiter - to probe the dusty surroundings of a newborn star and discover some of its innermost secrets. These findings shed new light on one of the most fundamental processes in the Universe, the creation of stars.
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=50462
Final cry of disrupted star points to site of oblivion03 Aug 2012
Astronomers have detected tell-tale luminosity fluctuations in the X-ray signal from a star that was torn apart and devoured by the supermassive black hole at the centre of a distant galaxy. The fluctuations, which have a period of 200 seconds, originate from the innermost stable orbit around the black hole and represent the last signal sent by the debris of the disrupted star before disappearing beyond the black hole's event horizon. The discovery, based on data from ESA's XMM-Newton and the Japan/US Suzaku space observatories, has allowed astronomers to probe the details of matter accretion onto a supermassive black hole in the distant Universe for the first time.
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=50638
XMM-Newton Announcement of Opportunity (AO-12) 21 Aug 2012
Proposals are solicited for observations with XMM-Newton in response to the twelfth Announcement of Opportunity, AO-12, issued 21 August 2012. This AO covers the period May 2013 to April 2014 and is open to proposers from all over the world.
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=50672
Fire burn and cauldron bubble
A giant bubble blown by the massive Wolf-Rayet star HD 50896, the pink star in the centre of the image.
X-ray data from XMM-Newton’s EPIC camera are shown in blue, while optical images were acquired using the Michigan Curtis Schmidt Telescope at Cerro Tololo Inter-American Observatory (CTIO) and presented in red (H-alpha) and green (OIII).
The bubble, known as S 308, is about 60 light-years across and is located 5000 light-years away in the constellation of Canis Major.
Credits: ESA, J. Toala & M. Guerrero (IAA-CSIC), Y.-H. Chu & R. Gruendl (UIUC), S. Arthur (CRyA–UNAM), R. Smith (NOAO/CTIO), S. Snowden (NASA/GSFC) and G. Ramos-Larios (IAM)
Weakling magnetar reveals hidden strength14 August 2013
Astronomers using ESA's XMM-Newton have measured the magnetic field in a small surface feature of a magnetar - a highly magnetised pulsar - for the first time. Until now, only the dipolar magnetic field of magnetars had been measured. With a new technique, the astronomers have now revealed a strong, localised surface magnetic field in the magnetar that had the lowest measured dipolar field. The discovery yields conclusive proof that magnetars conceal some of the strongest magnetic fields in the Universe.
http://sci.esa.int/xmm-newton/52772-weakling-magnetar-reveals-hidden-strength/Image credit: ESA/ATG medialab
Volatile pulsar reveals millisecond missing link25 September 2013
For the first time, astronomers have caught a pulsar in a crucial transitional phase that explains the origin of the mysterious millisecond pulsars. These pulsars spin much faster than expected for their old age, and astronomers believe their rotation receives a boost as they accrete matter in a binary system. The newly found pulsar swings back and forth between accretion-powered X-ray emission and rotation-driven radio emission, bringing conclusive evidence for their 'rejuvenation'. The discovery was made possible by the coordinated efforts of ESA's two missions that scan the high-energy sky: INTEGRAL and XMM-Newton.
http://sci.esa.int/integral/52866-volatile-pulsar-reveals-millisecond-missing-link/
Unravelling the Cosmic Web: Survey gives insights into Universe's structure15 December 2015
Today marks the release of the first papers to result from the XXL survey, the largest survey of galaxy clusters ever undertaken, carried out with ESA's XMM-Newton X-ray observatory. The gargantuan clusters of galaxies surveyed are key features of the large-scale structure of the Universe and to better understand them is to better understand this structure and the circumstances that led to its evolution. The first results from the survey, published in a special issue of Astronomy and Astrophysics, hint at the answers and surprises that are captured in this unique bank of data and reveal the true potential of the survey.
http://sci.esa.int/xmm-newton/57031-unravelling-the-cosmic-web-survey-gives-insights-into-universes-structure/Image credit: ESA/XMM-Newton/XXL survey consortium
Space selfieLaunched on 10 December 1999, XMM-Newton is an X-ray observatory designed to investigate some of the most violent phenomena in the Universe. Sources that emit large amounts of X-rays include remnants of supernova explosions and the surroundings of black holes.
Detecting this energetic radiation is a daunting endeavour, requiring techniques that are greatly different from those used in traditional telescopes. In the case of XMM-Newton, it carries three telescopes of 58 nested mirrors each. These sit at one end of a 7 m-long tube, while at the other end are the scientific instruments at the focus.
The two images in this collage were taken by the two low-resolution monitoring cameras mounted on opposite sides of the focal plane assembly, looking along the pointing direction of the telescope tube towards the service module (see below for an annotated version with explanation).
The cameras were originally used by controllers to check how the solar wings unfolded after launch, and have remained dormant since 2003.
When these images were captured on 14 September 2016 at 06:50 GMT, XMM-Newton was in its 3070th orbit at around 50 000 km altitude and in contact with mission controllers at ESA’s mission control in Darmstadt, Germany, via the antenna at Kourou, French Guiana.
http://www.esa.int/spaceinimages/Images/2016/12/Space_selfie
The brightest furthest pulsar in the Universe21 February 2017
ESA's XMM-Newton has found a pulsar – the spinning remains of a once-massive star – that is a thousand times brighter than previously thought possible.
The pulsar is also the most distant of its kind ever detected, with its light travelling 50 million light-years before being detected by XMM-Newton.
http://sci.esa.int/xmm-newton/58817-the-brightest-furthest-pulsar-in-the-universe/Image credit: ESA/XMM-Newton; NASA/Chandra and SDSS
WHERE IS THE UNIVERSE'S MISSING MATTER?18 April 2018
Astronomers using ESA's XMM-Newton space observatory have probed the gas-filled haloes around galaxies in a quest to find 'missing' matter thought to reside there, but have come up empty-handed – so where is it?
http://sci.esa.int/xmm-newton/60173-where-is-the-universes-missing-matter/Image credit: ESA/XMM-Newton; J-T. Li (University of Michigan, USA); Sloan Digital Sky Survey (SDSS)
20 years in space next year, and still running, and still productive. Must be ESA longest mission ever, by a large margin.
It is really ESA very own Hubble, albeit a little less glamourous.
Just wondering, why this and some other ESA, and possibly other, mission are not in space science section?
Because the section didn't exist when old mission threads were created. Moved to its appropriate section.
Not even NSF existed when it was launched. Well, Internet itself had barely happened when it launched... (was in high school back then. Is that so far away ?

)
20 years in space next year, and still running, and still productive. Must be ESA longest mission ever, by a large margin.
It is really ESA very own Hubble, albeit a little less glamourous.
ESAs Integral
https://en.wikipedia.org/wiki/INTEGRAL was launched in 2002 and is still operating, so I don't know that Xmm stands out particularly by its lifetime.
And if you allow joint missions then SOHO was built by European partners, launched in 1995, and still working.
COSMIC BLAST TAKES REST AT LAST31 May 2018
Last year, the first detection of gravitational waves linked to a gamma-ray burst triggered a vast follow-up campaign with ground and space telescopes to study the aftermath of the neutron star merger that gave rise to the explosion. ESA's XMM-Newton observations, obtained a few months after the discovery, caught the moment when its X-ray emission stopped increasing, opening new questions about the nature of this peculiar source.
http://sci.esa.int/xmm-newton/60376-cosmic-blast-takes-rest-at-last/Image credit: ESA/XMM-Newton; P. D'Avanzo (INAF–Osservatorio Astronomico di Brera)
STAR SHREDDED BY RARE BREED OF BLACK HOLE18 June 2018
ESA's XMM-Newton observatory has discovered the best-ever candidate for a very rare and elusive type of cosmic phenomenon: a medium-weight black hole in the process of tearing apart and feasting on a nearby star.
There are various types of black hole lurking throughout the Universe: massive stars create stellar-mass black holes when they die, while galaxies host supermassive black holes at their centres, with masses equivalent to millions or billions of Suns.
Lying between these extremes is a more retiring member of the black hole family: intermediate-mass black holes. Thought to be seeds that will eventually grow to become supermassive, these black holes are especially elusive, and thus very few robust candidates have ever been found.
Now, a team of researchers using data from ESA's XMM-Newton X-ray space observatory, as well as NASA's Chandra X-Ray Observatory and Swift X-Ray Telescope, has found a rare telltale sign of activity. They detected an enormous flare of radiation in the outskirts of a distant galaxy, thrown off as a star passed too close to a black hole and was subsequently devoured.
http://sci.esa.int/xmm-newton/60424-star-shredded-by-rare-breed-of-black-hole/Image credit: ESA/XMM-Newton/UNH/D.Lin et al; Acknowledgement: NASA/CXC