Using NASA’s Hubble Space Telescope, the team took hundreds of high-resolution photos and compared the images pixel-by-pixel to identify the dimmest stars in the globular star cluster NGC 6397.
“The light from these faint stars is so dim that it is equivalent to that produced by a birthday candle on the Moon, as seen from Earth,” says Richer, lead investigator of the project, which was chosen over several thousand other proposals to gain almost five days access to Hubble.
The team surveyed two distinct stellar populations -- red dwarfs and white dwarfs -- in NGC 6397. Located in the southern constellation Ara, approximately 8,500 light-years away, NGC 6397 is the second closest globular star cluster to Earth.
At approximately eight per cent the mass of the Sun, the lowest mass red dwarfs are the least massive stars in the Universe still capable of burning hydrogen in their cores and supporting stable nuclear reactions.
White dwarfs are the burnt out remnants of more massive stars that died long ago. By measuring the temperatures of white dwarfs -- much like checking the temperature of smoldering coals in a campfire to estimate how long ago it was burning -- astronomers are able to determine the star’s age. This information provides important clues to the age of the globular cluster, which formed in the early Universe.
Analysing this relic population of white dwarfs is also the only way to calculate the original number of high-mass stars in the cluster.
“These stars, which died long ago, were among the first to have formed in the Universe,” says Richer, the world’s leading expert in using white dwarfs as a tool for dating globular clusters. “Pinning down their age narrows down the age range of the Universe.”
NB: Detailed results will be published in the Aug. 18 edition of the journal Science. For an advance copy of the paper, contact Natasha Pinol, AAAS / Science at 202.326.7088 or email@example.com.
Prof. Richer will present the team’s findings at an Aug. 17 press conference during the General Assembly of the International Astronomical Union (IAU) in Prague. For more information, visit http://www.astronomy2006.com.
Electronic images are available at http://hubblesite.org/news/2006/37/.
High-resolution photos of Prof. Richer and star cluster NGC 6397 is available at http://www.publicaffairs.ubc.ca/download/.Biography: Harvey B. Richer
Richer has been at the University of British Columbia since the early 1970s. He has received various awards and distinctions including: Canada-U.S. Fulbright Scholar (2005), Canada Council for the Arts Killam Fellowship (2001-03), and the Gemini Scientist for Canada (2000-03).
His research is largely focused on stellar astronomy and on what resolved systems of stars can tell us about dark matter, the age of the Universe, the dynamical evolution of stellar systems, and the formation of galaxies. To investigate these diverse subjects, he observes a wide range of objects, including nearby stars, open and globular star clusters, and the resolved components of our neighbouring galaxies.
To accomplish his research goals, he uses a variety of telescopes, particularly the Twin Gemini Telescopes, the Canada-France-Hawaii Telescope and the Hubble Space Telescope.
Randy Schmidt | EurekAlert!
APEX takes a glimpse into the heart of darkness
25.05.2018 | Max-Planck-Institut für Radioastronomie
First chip-scale broadband optical system that can sense molecules in the mid-IR
24.05.2018 | Columbia University School of Engineering and Applied Science
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
25.05.2018 | Life Sciences
25.05.2018 | Interdisciplinary Research
24.05.2018 | Ecology, The Environment and Conservation