Twinkle, Twinkle, Little Star

No one can quite encapsulate the depth and breadth of the universe in relation to our speck-like existence, such as the well-known astronomer Carl Sagan, who takes credit for writing The Pale Blue Dot and Cosmos. In his book, the astronomer postulates that the “universe is within us” and that “we are made of star-stuff.” Sagan further elaborated his point in a subsequent excerpt by pointing out specific elements that we have in common with the stars: the nitrogen that holds DNA molecules together, the calcium that hardens our bones, the iron that enables the blood to gather oxygen, and the carbon that makes up the fruits we eat—these are the same elements that make up the cores of stars.

As children, we were often taught by our parents to sing Twinkle, twinkle, little star, a ritual before sleeping. However, if we study these celestial bodies closely, they aren’t technically twinkling.

Stars are massive celestial objects mainly made up of hydrogen and helium. As a result of the nuclear factory within the stars’ cores, it emits light. Before this light reaches the Earth, it passes through the atmosphere, which is made up of different layers. When the light hurdles through these different atmospheric layers, it gives off the appearance of twinkling. To further observe the certain intricacies of stars, one needs to make investments in a telescope.

It is also worth noting that the stars we see at night aren’t only made up of a single type. Stars are categorized according to their color and brightness.

Solar-Type Stars

Solar-Type stars are, to a certain degree, similar to the sun in their mass and evolution. Due to their similar structures, the solar-type stars emit a kindred yellow glow that is common to most stars that we see in the sky. This emission of light allows the star to live a stable life for a relatively longer period of time.

A notable star of this type is Alpha Centauri, which is closest to the Earth at 4.37 light-years from the sun.

Hot Blue Stars

The colors of the stars are parameters in measure temperature: hot stars appear blue, while cool stars appear red. A star’s color is also proportional to its mass. Blue stars weigh at least three times heavier than the sun. If you ever decide to peer up at the sky on a cloudless night, remember that the blue blips of light you can see are stars that can most likely be bigger than the sun.

One of the most prominent of this star type is Rigel, the most radiant from the Orion constellation and is the 6th brightest star in the galaxy. This star is situated at around 900 light-years away.

Red Dwarf Stars

In contrast to the Hot Blue Stars, the Red Dwarf Stars are relatively cooler, which means that they don’t use up much of the nuclear energy within their cores, leading to a relatively longer existence. These types of stars are the most dominant in the galaxy.

Examples of prominent Red Dwarf Stars are the Proxima Centauri and the Barnard’s Star. However, one needs to have a telescope investment in order to see these celestial bodies.

Red Giant Stars

Recall that a star is powered by the nuclear forces within its core. When a star’s supply of hydrogen is used up within its core, it uses up the hydrogen external to its core. As a result, the star swells. In the simplest sense, these giant stars signal the last stages of stellar evolution, perhaps the last thousand years of a star’s existence.

Betelgeuse is a Red Giant forming the shoulder of Orion.

White Dwarfs

When virtually all of the stars’ fuel is depleted, it disintegrates until only its core remains. It is immensely hot and emits large amounts of ultraviolet light (which is part of the invisible light spectrum).

An example of this celestial beauty is Sirius, found in the constellation of Canis Major.

Neutron Stars and Black Holes

When a star ten times more massive than the sun depletes the last remaining molecules of its nuclear fuel, a huge portion of its mass flows into its core. Gravity, the relentless adhesive, packs every subatomic particle so tightly that protons fuse with electrons. Hence, referring to them as Neutron stars.

Neutron stars are the epitome of density. A teaspoon of a neutron star would weigh more than a million tons. It is worth noting that the gravitational force surrounding a neutron star is two billion times stronger than that of the Earth’s.