Starsglaxiesspace - SPACE

Dragon Attached to Station for Month of Cargo Transfers

SpaceX - CRS-13 Dragon Mission patch. Dec. 17, 2017

Image above: The Dragon resupply ship is pictured just 10 meters away from the space station’s Canadarm2. Image Credit: NASA TV. The SpaceX Dragon cargo spacecraft was installed on the Harmony module of the International Space Station at 8:26 a.m. EST. The 13th contracted commercial resupply mission from SpaceX (CRS-13) delivered more than 4,800 pounds of supplies and payloads to the station. Among the research materials flying inside Dragon’s pressurized area, one investigation will demonstrate the benefits of manufacturing fiber optic filaments in a microgravity environment. Designed by the company Made in Space, and sponsored by the Center for the Advancement of Science in Space (CASIS), the investigation will attempt to pull fiber optic wire from ZBLAN, a heavy metal fluoride glass commonly used to make fiber optic glass. Results from this investigation could lead to the production of higher-quality fiber optic products for use in space and on Earth.

U.S. Commercial Cargo Ship Arrives at the Space Station

Dragon is scheduled to depart the station in January 2018 and return to Earth with more than 3,600 pounds of research, hardware and crew supplies. Loaded with some three tons of experiments and supplies, the SpaceX Dragon cargo craft arrived at the International Space Station Dec. 17, where Expedition 53 crew members Mark Vande Hei and Joe Acaba of NASA captured it by using the Canadian-built robotic arm.

Image above: Dec. 17, 2017: International Space Station Configuration. Four spaceships are parked at the space station including the SpaceX Dragon space freighter, the Progress 67 and 68 resupply ships and the Soyuz MS-06 crew ship. Image Credit: NASA TV. Ground controllers at NASA’s Johnson Space Center in Houston took over after Dragon was grappled, sending commands to maneuver the ship to the Earth-facing side of the Harmony module where it was attached for a month-long stay. Dragon was launched Dec. 15 on the SpaceX Falcon 9 rocket from Complex 40 at the Cape Canaveral Air Force Station in Florida to begin its journey to the international outpost. Related links: Debris Sensor (SDS): https://www.nasa.gov/mission_pages/station/research/experiments/2145.html Center for the Advancement of Science in Space (CASIS): http://www.iss-casis.org/ Total and Spectral Solar Irradiance Sensor, or TSIS-1: http://www.nasa.gov/tsis-1 SpaceX: http://www.nasa.gov/spacex Commercial Resupply: http://www.nasa.gov/mission_pages/station/structure/launch/index.html Expedition 54: https://www.nasa.gov/mission_pages/station/expeditions/future.html International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html Images (mentioned), Video (NASA TV), Text, Credits: NASA/Mark Garcia. Greetings, Orbiter.ch Full article

Weighing massive stars in nearby galaxy reveals excess of heavyweights

Weighing massive stars in nearby galaxy reveals excess of heavyweights An international team of astronomers has revealed an ‘astonishing’ overabundance of massive stars in a neighbouring galaxy.

The discovery, made in the gigantic star-forming region 30 Doradus in the Large Magellanic Cloud galaxy, has 'far-reaching’ consequences for our understanding of how stars transformed the pristine Universe into the one we live in today.

The results are published in the journal Science.

Lead author Fabian Schneider, a Hintze Research Fellow in the University of Oxford’s Department of Physics, said: 'We were astonished when we realised that 30 Doradus has formed many more massive stars than expected.’

As part of the VLT-FLAMES Tarantula Survey (VFTS), the team used ESO’s Very Large Telescope to observe nearly 1,000 massive stars in 30 Doradus, a gigantic stellar nursery also known as the Tarantula nebula.

The team used detailed analyses of about 250 stars with masses between 15 and 200 times the mass of our Sun to determine the distribution of massive stars born in 30 Doradus - the so-called initial mass function (IMF).

Massive stars are particularly important for astronomers because of their enormous influence on their surroundings (known as their 'feedback’). They can explode in spectacular supernovae at the end of their lives, forming some of the most exotic objects in the Universe - neutron stars and black holes.

Co-author Hugues Sana from the University of Leuven in Belgium said: 'We have not only been surprised by the sheer number of massive stars, but also that their IMF is densely sampled up to 200 solar masses.’

Until recently, the existence of stars up to 200 solar masses was highly disputed, and the study shows that a maximum birth mass of stars of 200-300 solar masses appears likely.

In most parts of the Universe studied by astronomers to date, stars become rarer the more massive they are. The IMF predicts that most stellar mass is in low-mass stars and that less than 1% of all stars are born with masses in excess of ten times that of the Sun.

Measuring the proportion of massive stars is extremely difficult - primarily because of their scarcity - and there are only a handful of places in the local Universe where this can be done.

The team turned to 30 Doradus, the biggest local star-forming region, which hosts some of the most massive stars ever found, and determined the masses of massive stars with unique observational, theoretical and statistical tools. This large sample allowed the scientists to derive the most accurate high-mass segment of the IMF to date, and to show that massive stars are much more abundant than previously thought.

Chris Evans from the Science and Technology Facilities Council’s UK Astronomy Technology Centre, the principal investigator of VFTS and a co-author of the study, said: 'In fact, our results suggest that most of the stellar mass is actually no longer in low-mass stars, but a significant fraction is in high-mass stars.’

Stars are cosmic engines and have produced most chemical elements heavier than helium, from the oxygen we breathe every day to the iron in our blood. During their lives, massive stars produce copious amounts of ionising radiation and kinetic energy through strong stellar winds. The ionising radiation of massive stars was crucial for the re-brightening of the Universe after the so-called Dark Ages, and their mechanical feedback drives the evolution of galaxies.

Philipp Podsiadlowski, a co-author of the study from the University of Oxford, said: 'To quantitatively understand all these feedback mechanisms, and hence the role of massive stars in the Universe, we need to know how many of these behemoths are born.’

Fabian Schneider added: 'Our results have far-reaching consequences for the understanding of our cosmos: there might be 70% more supernovae, a tripling of the chemical yields and towards four times the ionising radiation from massive star populations. Also, the formation rate of black holes might be increased by 180%, directly translating into a corresponding increase of binary black hole mergers that have recently been detected via their gravitational wave signals.’

The team’s research leaves many open questions, which they intend to investigate in the future: how universal are the findings, and what are the consequences of this for the evolution of our cosmos and the occurrence of supernovae and gravitational wave events?

Mova Globes