Using NASA’s Hubble Space Telescope, astronomers have captured for the first time snapshots of fledging white dwarf stars beginning their slow-paced, 40-million-year migration from the crowded center of an ancient star cluster to the less populated suburbs.
White dwarfs are the burned-out relics of stars that rapidly lose mass, cool down and shut off their nuclear furnaces. As these glowing carcasses age and shed weight, their orbits begin to expand outward from the star cluster’s packed downtown. This migration is caused by a gravitational tussle among stars inside the cluster. Globular star clusters sort out stars according to their mass, governed by a gravitational billiard ball game where lower mass stars rob momentum from more massive stars. The result is that heavier stars slow down and sink to the cluster’s core, while lighter stars pick up speed and move across the cluster to the edge. This process is known as “mass segregation.” Until these Hubble observations, astronomers had never definitively seen the dynamical conveyor belt in action.
Astronomers used Hubble to watch the white-dwarf exodus in the globular star cluster 47 Tucanae, a dense swarm of hundreds of thousands of stars in our Milky Way galaxy. The cluster resides 16,700 light-years away in the southern constellation Tucana.
NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission.
Seven metals are associated with the seven classical planets, and seven deities, all figuring heavily in alchemical symbolism. Although the metals occasionally have a glyph of their own, the planet’s symbol is used most often, and the symbolic and mythological septenary is consistent with Western astrology. The planetary symbolism is limited to the seven wandering stars visible to the naked eye, and the extra-Saturnarian planets such as Neptune are not used.
Gold dominated by Sol ☉ ☼ Silver dominated by Luna ☽ Copper dominated by Venus ♀ Iron dominated by Mars ♂ Tin dominated by Jupiter ♃ Mercury (quicksilver) dominated by Mercury ☿ Lead dominated by Saturn ♄
In this mesmerizing view of a stellar nursery by the ESO’s Very Large Telescope (VLT) in Chile, a stunning celebration is underway.
Located some 22,000 light-years from Earth, this star-forming nebula is undergoing dramatic changes. Deep within the cloud of cool hydrogen gas, young stars cook the region from the inside-out, driving hot ionized gas to the edge of the cloud, bursting into the interstellar medium like the bubbling foam of a popped champagne bottle. Learn more
In Laser Thruster Advance, Light Alone Pushes a Sled Down a Track
Here is the latest demonstration of a propulsion technology called a photonic laser thruster. In it, NASA Innovative Advanced Concepts Fellow Young Bae moved a one-pound object on a track using light alone for the first time.
The hope is that a laser fired from one spacecraft to another will provide enough push to make this form of propulsion viable for interplanetary travel. Back in 2013, the agency expanded research on the concept of photonic laser thrusters after discovering it could have “a much larger potential in NASA mission applications.”