Nasa's Hubble Captures Stunning Image Of The Red Spider Nebula

RED SPIDER NEBULA

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Context

NASA posted image about the Red Spider Nebula, which is 3,000 light-years from Earth and can be found in the constellation of Sagittarius.

What is a Nebula?

A nebula is a vast cloud of gas and dust in space.
It primarily consists of hydrogen and helium, along with traces of heavier elements like carbon, oxygen, and nitrogen.
It is considered the birthplace of stars.
Stars form inside nebulae when regions within the cloud collapse under gravity, eventually igniting nuclear fusion and shining as new stars.
These stellar nurseries are essential for the continual generation of new stars in the universe.

Source: Britannica

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STELLAR FORMATION

Main Sequence: Stars spend most of their lives in this stage. During this phase, hydrogen in the core fuses into helium, releasing energy and causing the star to shine.

Red Giant Phase: As hydrogen runs out, the core contracts while the outer layers expand and cool, forming a red giant. The star’s brightness increases, but its surface temperature decreases, giving it a reddish color.

Fate of Small Stars:

●Planetary Nebula Phase: The outer layers of the red giant are ejected, creating a cloud of gas known as a planetary nebula.

●White Dwarf: What remains is the core, which becomes a dense, hot white dwarf. Over billions of years, this cools down and eventually becomes a black dwarf, though no black dwarfs exist yet, as the universe is not old enough.

Fate of Massive Stars:

●Supernova: Massive stars undergo a violent explosion called a supernova, scattering elements into space, which can form new stars.

●Neutron Star or Pulsar: If the remaining core is dense enough, it forms a neutron star. If the neutron star rotates rapidly and emits beams of radiation, it becomes a pulsar.

●Black Hole: If the star is extremely massive, the core collapses into a black hole, an object with such strong gravitational pull that not even light can escape.

Types of Nebulae

Name	Description
Emission Nebula	●These nebulae emit their own light due to ionized gases, particularly hydrogen. ●For example, Orion Nebula.
Reflection Nebula	●These don't emit light on their own but reflect light from nearby stars. ●The light tends to appear blue due to scattering, similar to how Earth's sky appears blue. ●For example, the Pleiades Nebula.
Planetary Nebula	●These are formed when a dying star expels its outer layers, which are then illuminated by the remaining hot core. ●The Ring Nebula is a famous example.
Dark Nebula	●These dense clouds of gas and dust block light from stars or nebulae behind them, making them appear as dark patches in the sky. ●The Horsehead Nebula is an example.
Supernova Remnant	●When a massive star explodes in a supernova, the material ejected forms a nebula. ●The Crab Nebula is an example of this type.

What is a Constellation?

A constellation is a group of stars that form a recognizable pattern in the night sky.
Constellations have been used since ancient times for navigation, storytelling, and astronomy.
There are 88 recognized constellations today, categorized by the International Astronomical Union (IAU).
In navigation, there are instances where the constellations would be utilized by sailors, like Polaris, commonly known as the North Star, to keep direction while on the sea.

Famous Constellations

Orion: One of the most identifiable constellations, by its belt of three stars, takes its name from a hunter in Greek mythology.
Ursa Major: Known also as the Great Bear, Ursa Major contains the famous asterism commonly called the Big Dipper, utilized to find the North Star.
Cassiopeia: This "W"-shaped constellation is named after a queen in Greek mythology and can be seen year-round in the Northern Hemisphere.
Scorpius: Its bright star Antares gives Scorpius its scorpion-like shape, and it is among the most prominent constellations of the southern sky.

Sagittarius

Sagittarius is an easily recognizable constellation located in the southern sky and is affiliated with a mythological figure-a centaur, half-man-half-horse, with a bow and arrow.
It contains a number of nebulae and star clusters.
It lies between Scorpius and Capricornus; the constellation appears during summer if one is in the Northern Hemisphere.
Sagittarius is in the direction of the center of the Milky Way galaxy.
The supermassive black hole lying at the center of the galaxy - Sagittarius A* - is within this constellation.

Read about Hubble: https://www.iasgyan.in/daily-current-affairs/hubble-telescope-23#:~:text=Contributions%20of%20Hubble%20Telescope,which%20the%20universe%20is%20expanding.

Sources:

DOWNTOEARTH

PRACTICE QUESTION

Q:Consider the following statements in reference to famous constellations:

1.The Big Dipper is part of the constellation Ursa Minor.

2.Orion is a constellation that is located on the celestial equator.

3.The Southern Cross is a constellation that is located in the northern hemisphere.

Which of the above statements is/are correct?

a) 1 and 2 only

b) 2 and 3 only

c) 1 and 3 only

d) 2 only

Answer: d

Explanation:

1^st statement is incorrect: The Big Dipper is an asterism that is part of the constellation Ursa Major (the Great Bear). The Big Dipper is one of the most recognizable constellations in the night sky, and it is often used to find other constellations.

2^nd statement is correct: Orion is a constellation that is located on the celestial equator. Orion is one of the brightest constellations in the night sky, and it is home to several bright stars, including Betelgeuse, Rigel, and Saiph.

3^rd statement is incorrect: The Southern Cross is a constellation that is located in the southern hemisphere. The Southern Cross is one of the most recognizable constellations in the southern night sky, and it is often used to find other constellations.