March 14 2021
During its period 31 years of activitiesTom Brown, an astronomer of Space Telescope Science, said that the Hubble Space Telescope has been “one of the most successful scientific experiments in history” and has been used to study many fields of astronomy, from cosmology and cosmic expansion to the characterization of exoplanets. . The Institute’s online presentation on March 2.
United NASA/European Space Agency This project was initiated by Hubble in 1990. Through maintenance tasks between then and 2009, it has become more and more powerful.
The telescope orbits the earth at an altitude of 333 miles (536 kilometers), and it takes 95 minutes to orbit the earth. When crossing the earth during the day, it is powered by solar panels; when crossing the night sky, it is powered by batteries.
The scientific instruments currently operating on the Hubble Telescope include a cosmic origin spectrometer that performs weak ultraviolet spectroscopy; a space telescope imaging spectrometer that can perform spectroscopy and imaging under optical and ultraviolet light; and an advanced survey camera (ACS) that can perform a wide field of view Imaging and slit-free spectral analysis; Wide-angle camera 3 (WFC3), which can also perform wide-area imaging and seamless spectroscopy and astronomical measurement; As well as fine guidance sensors for astronomical measurement and as a pointing control system.
Brown said Hubble’s advantage is that it combines powerful imaging and spectroscopy capabilities. Its UV imaging capability is especially important because it cannot image UV from the ground.
Spectroscopy disperses the light from its light source into its component colors, “providing information for astrophysics research related to temperature and chemistry.”
Hubble is not only used to image the massive star Eta Carinae to show its structure, but also to perform spectral analysis to reveal its chemical composition.
Brown emphasized that the functions of ACS and WFC3 are much more powerful than the previous generation of Hubble instruments.
Hubble photographed many nearby galaxies, many of which are spiral galaxies, and galaxies farther away. “Now, when we use the Hubble Telescope to obtain images, we not only get the object we are observing, but we also tend to get most of the universe behind the object for free under the same exposure.” Brown said, this is for the early Ha Bo camera is impossible.
Hubble’s science includes studies on the Milky Way, the medium of the Milky Way and around the Milky Way, large-scale structures, the solar system, stellar physics, stellar populations, supermassive black holes, exoplanets and planet formation.
Each year, about 1,000 peer-reviewed papers are published based on Hubble data. These include papers by scientists, which are returned to the Hubble Archives, and use these data for new scientific research.
Brown said that Hubble is rewarded for observing time through a double anonymous peer review system to avoid prejudice. The telescope’s demand for time exceeds five to one of its available time.
He said that the two phenomena that Hubble has studied the most are universe expansion and exoplanet science.
A lot of scientific work can be done through enhanced gravitational lensing, which allows astronomers to see very distant objects, including galaxies that are ten times dimmer than could be observed.
Since the launch of the telescope, measuring the expansion of the universe or the expansion of the universe has been a priority. Scientists at the time hoped to use Hubble to describe the rate of expansion of the universe.
It was not known at the time, but through subsequent observations of supernovae, it was discovered that the expansion of the universe experienced periods of deceleration and acceleration.
“We are now in the era of precision cosmology, and people are using different methods to measure the expansion of the universe’s rate. Those methods do not always give the same answer, which may imply new physics.”
Exoplanet research now accounts for 20% of Hubble’s observation time. But when Hubble launched, no exoplanets had been discovered.
Hubble is not the main facility for discovering exoplanets, but it is the main facility for studying the exoplanet atmosphere. Once other facilities find planets, they are used for follow-up observations.
The Hubble Telescope measures the change in light that occurs when an orbiting planet passes in front of its star.
The oldest known exoplanet orbited a pulsar in 1992. Three years later, scientists discovered the first exoplanet orbiting a normal star. Today, thousands of exoplanets have been discovered and continue to be discovered.
A technique called space scanning developed over the past decade involves deliberately dragging the telescope across the entire field of view. This allows scientists to obtain high-precision parallax and astronomical measurements, and obtain measurements of hundreds of star positions.
Hubble is also used in conjunction with NASA and ESA missions.scientists New horizons The Pluto mission used it to navigate the spacecraft’s safe path to the debris, found four small satellites orbiting Pluto, and identified the second overflight target, the Kuiper belt object, Arrokoth.
assist Juno During the Jupiter mission, scientists have been observing large planets with Hubble. At the same time, Juno is also observing at close range, and researchers are studying natural gas giants with ground-based observation capabilities. Gemini Observatory In Hawaii.
Researchers are using the Hubble Telescope to study the properties of black holes and the disks of matter falling into them, and to further understand gravitational waves, which are ripples in the space-time structure formed by the merger of two huge objects, such as neutron stars or black holes .
When it was in service for the last time in 2009, scientists hoped that the Hubble Telescope would last until 2016. After fulfilling these expectations, it is now expected that it will play an important role in astrophysics research in the next decade.
Hubble, together with the James Webb Space Telescope scheduled to launch later this year, will further explore the expansion and dark energy of the universe, provide new insights into exoplanets and their atmospheres, cooperate with solar system exploration missions, and help scientists understand other planets Of discovery facilities.
Video provided by the Space Telescope Science Institute
Laurel Kornfeld is an amateur astronomer and freelance writer from Highland Park, New Jersey. He likes to write articles about astronomy and planetary science. She studied journalism at Douglas College, Rutgers University, and received a Master of Science in Astronomy Online Course from Swinburne University. Her work has been published online in The Atlantic, the guest blog section of Astronomy magazine, the British Space Conference, the 2009 International Astronomical Union newspaper, the Space Reporter, and the newsletters of various astronomy clubs. She is a member of amateur astronomers based in Cranford, New Jersey. Particularly interested in the outer solar system, Laurel gave a brief introduction at the 2008 Great Planets Debate held at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.