Astronomy Current Affairs

Enter Your Email Address To Subscribe Current Affairs Daily Digest, Daily Quiz and other updates on Current Affairs:

Astronomers discover Venus-like planet orbiting a dim star Kepler-1649

Astronomers using NASA’s Kepler space telescope have discovered a Venus-like planet orbiting a dim star called Kepler-1649.

The newly found planet is one-fifth the diameter of our Sun and is only slightly larger than Earth. It is located 219 light years away from Earth.

Key Facts
  • The Venus-like planet tightly embraces its low-temperature star Kepler-1649 by encircling it every nine days.
  • The tight orbit around the star causes the flux of sunlight reaching it to be 2.3 times as great as the solar flux on Earth. For comparison, the solar flux on Venus is 1.9 times the terrestrial value (on earth).
  • The discovery will provide insight into the nature of planets encircling around M dwarf stars, by far the most common type in the universe.

About Venus

  • Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. It is named after the Roman goddess of love and beauty.
  • It is a terrestrial planet and is sometimes called Earth’s “sister planet” because of their similar size, mass, proximity to Sun, and bulk composition. It has no natural satellite.
  • But it is radically different from Earth in other respects. It has densest atmosphere of four terrestrial planets, consisting of more than 96% CO2. The atmospheric pressure at its planet’s surface is 92 times that of Earth.
  • Note: Venus is by far the hottest planet in the Solar System, with a mean surface temperature 462 °C even though Mercury is closer to the Sun.

About Kepler Space Telescope (KST)

  • KST is an unmanned space observatory launched in 2009 by National Aeronautics and Space Administration (NASA).
  • It is tasked with determining how commonly, Earth-like planets occur throughout the Milky Way galaxy.
  • KST works by observing a dimming in the light of a star, known as a transit, each time an orbiting planet passes in front of it.
  • It has been designed for a statistical mission and not to probe into the environmental conditions of planets that exist in the so-called Goldilocks zone (Habitable zone) of their stars.

Tags:

Scientists for first time saw eclipses of binary star shed light on orbiting exoplanet

A team of scientists from Raman Research Institute, Bengaluru and University of Delhi for the first time have seen indications of a massive planet orbiting a low mass X-ray binary star system.

The system MXB 1658-298 is an X-ray binary and a part of the constellation Ophiuchus (serpent bearer). It is nearly 30,000 light years away and the planet is expected to be nearly 8,000 times as massive as the earth. 

Key Facts
  • X-ray binaries consist of a pair of stars orbiting each other of which one is compact one such as a black hole or a neutron star.
  • In this case it is a neutron star which draws matter from its less-massive companion and generates X-rays which are detected by detectors placed in satellites in space.
  • This discovery is made with a new technique, X-Ray observation by measuring periodic delays in X-ray eclipses. It is a new technique of detecting exoplanets and observations are done from space observatories.
  • In X-ray binaries, the time in-between eclipses of the source can increase, decrease and also shows abrupt changes. But in MXB 1658-298, time between the eclipses increases and decreases periodically.

Tags:

Astronomers discover 7 new Earth-sized exoplanets that may sustain life

Astronomers from NASA (National Aeronautics and Space Administration) for the first time have discovered seven new Earth-sized exoplanets that may be able to sustain life.

The planets were detected using NASA’s Spitzer Space Telescope and several ground-based observatories including Trappist robotic telescope at La Silla, Chile. 

Key Facts
  • These exoplanets are orbiting dwarf star named Trappist-1, which at 39 light years away. They could have some liquid water and maybe supporting life.
  • Of the seven planets, three are classified as TRAPPIST-1 e, f and g. These three planets orbit in the habitable (so-called Goldilocks zone) where temperatures are suited to surface oceans of liquid water.
  • The star Trappist-1 is at least 500 million years old and has a temperature of 2550K. It is marginally larger than Jupiter and shines with a feeble light about 2,000 times fainter than Earth’s sun.
  • The 6 inner planets lie in a temperate zone where surface temperatures range from zero to 100C. Their masses range from around 0.4 to 1.4 times the mass of the Earth.
  • They are so close to each other that their gravitational fields interact with each other. However, their atmospheres needs more study before determining whether they could support some type of life. 
Astronomical terms
  • Exoplanet: It is a planet that does not orbit the Sun and instead orbits a different star, stellar remnant, or brown dwarf. It is also termed as extrasolar planet.
  • Goldilocks Zone: It refers to a habitable zone in space where the temperature is neither too high nor too low. Such conditions could allow for the presence on the planet’s surface of liquid water – a key ingredient for life.

Tags:

Advertisement

12345...10...10