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Using the Five-hundred Aperture Spherical Telescope (FAST), astronomers from China and Australia have discovered five new pulsars, two of which turned out to have ultra-short spin periods.
- The Five-hundred-meter Aperture Spherical radio Telescope (FAST) is a Chinese mega science project that began operations in 2016.
- Located in the Dawodang depression, Guizhou Province, China, it is the world's largest filled-aperture radio telescope.
Construction and Capabilities:
- FAST has a diameter of 500 meters, comprising 4,450 triangular panels.
- It is highly sensitive and has an enormous collecting area, allowing it to detect faint signals from the universe.
- The telescope's main goals include studying pulsars, detecting neutral hydrogen in distant galaxies, and searching for extraterrestrial intelligence (SETI) signals.
- Pulsar research: FAST has significantly contributed to the discovery of numerous pulsars, which are highly magnetized, rotating neutron stars that emit beams of electromagnetic radiation.
- Interstellar medium studies: FAST has helped in mapping the distribution of neutral hydrogen in the Milky Way and other galaxies, providing insights into the structure and evolution of the universe.
- SETI efforts: Its high sensitivity and large collecting area make it an excellent tool for the Search for Extraterrestrial Intelligence (SETI) projects.
- Exploring the origins and behavior of pulsars and understanding their role in the universe.
- Investigating the interstellar medium and the dynamics of galaxies, particularly the Milky Way.
- Enhancing the search for potential extraterrestrial intelligence by scanning the cosmos for artificial signals.
Definition and Nature:
- Pulsars are highly magnetized, rotating neutron stars that emit electromagnetic radiation along their magnetic axes.
- They were first discovered in 1967 by Jocelyn Bell Burnell and Antony Hewish.
Characteristics and Observations:
- Pulsars emit radiation in regular pulses, ranging from milliseconds to seconds.
- They have extremely stable rotational periods, making them valuable tools for studying gravitational waves and testing theories of general relativity.
- Pulsars are natural celestial clocks that help astronomers make precise measurements in astrophysics and cosmology.
Role in Astrophysics and Cosmology:
- Pulsars aid in the study of extreme physical conditions, such as high magnetic fields and dense matter, helping scientists understand the behavior of matter under such extreme circumstances.
- They provide evidence for the existence of gravitational waves and have contributed to our understanding of the universe's structure and evolution.
- Pulsar observations have also shed light on the dynamics of supernova explosions and the subsequent formation of neutron stars.
Recent Developments and Discoveries:
- Advances in pulsar timing techniques have led to the detection of gravitational waves and the study of their properties, confirming Einstein's theory of general relativity.
- Researchers have found pulsar planets, which are believed to have formed from the debris of supernovae, leading to a better understanding of planetary formation in extreme environments.
- Ongoing pulsar surveys have unveiled various types of pulsars, broadening our knowledge of stellar evolution and the behavior of matter under extreme conditions.
Notable radio telescopes
Radio telescopes play a crucial role in modern astronomy, allowing scientists to observe and study celestial objects and phenomena in the radio frequency range.
Arecibo Observatory (Puerto Rico, USA):
- The Arecibo Observatory was one of the most powerful radio telescopes until its collapse in 2020.
- It had a 305-meter dish and played a crucial role in radar observations of planets, studies of pulsars, and research on gravitational waves.
Atacama Large Millimeter Array (ALMA) (Chile):
- ALMA is a collection of 66 high-precision antennas used to observe the universe in the millimeter and submillimeter wavelength ranges.
- Located at an elevation of 5,000 meters in the Chilean Andes, ALMA allows scientists to study the formation of stars and planets, as well as galaxies in the early universe.
Very Large Array (VLA) (New Mexico, USA):
- The VLA is a collection of 27 radio antennas that can be arranged in different configurations to simulate a single large telescope.
- It is used to observe a wide range of astronomical objects, including pulsars, black holes, and star-forming regions.
Parkes Observatory (Australia):
- The Parkes Observatory, operated by the Commonwealth Scientific and Industrial Research Organisation (CSIRO), is known for its role in receiving the live television broadcast of the Apollo 11 moon landing.
- It continues to contribute to pulsar research, radio transient observations, and the study of the Milky Way's structure.
Jodrell Bank Observatory (United Kingdom):
- Home to the Lovell Telescope, Jodrell Bank Observatory has a rich history in radio astronomy.
- The Lovell Telescope has been used for a wide range of research, including the tracking of space missions, the study of quasars, and the observation of pulsars.
Effelsberg Radio Telescope (Germany):
- Operated by the Max Planck Institute for Radio Astronomy, the Effelsberg Radio Telescope is one of the largest fully steerable radio telescopes in the world.
- It is used for high-resolution mapping of neutral hydrogen in the Milky Way and other galaxies, as well as for the study of pulsars and active galactic nuclei.
Green Bank Observatory (West Virginia, USA):
- The Green Bank Observatory is known for its Green Bank Telescope (GBT), which is the world's largest fully steerable radio telescope.
- It is used for a variety of research, including studies of pulsars, the interstellar medium, and the search for extraterrestrial intelligence.
Giant Metrewave Radio Telescope (GMRT) (India):
- Located near Pune, India, the GMRT consists of an array of 30 fully steerable, gigantic parabolic antennas.
- It operates at meter wavelengths and is used for a variety of radio astronomical studies, including pulsar observations, studies of the interstellar medium, and research on active galaxies.
SARAS 3 (India):
- The SARAS 3 (Search for Axion-Like Particle Dark Matter Using a Radio Telescope Array) is an experimental radio telescope array located at the National Centre for Radio Astrophysics in Pune, India.
- It is used for studying axion-like particles, a hypothetical type of dark matter, through radio astronomy techniques.
Q. Which of the following statements about the Atacama Large Millimeter Array (ALMA) is/are correct?
1. ALMA is located in the Atacama Desert of southern Chile.
2. It consists of 50 high-precision antennas for observing the universe in the millimeter and submillimeter wavelength ranges.
3. ALMA is primarily used for studying visible light from distant galaxies.
a) 1 and 2 only
b) 1 and 3 only
c) 2 and 3 only
d) 1, 2, and 3