There are many different types of stars in the sky, classified based on their size,temperature,brightness and lifespan.

1. Main Sequence Stars: These are the most common type, fusing hydrogen into helium in their cores. They are divided into:

O-type (blue, massive, and extremely hot)
B-type (blue, hot, and luminous)
A-type (white, hot, and bright)
F-type (yellow-white, moderately hot)
G-type (yellow, like the Sun)
K-type (orange, cooler)
M-type (red, coolest and most common)

2. Red Giant Stars:

Cool, luminous stars that have exhausted their hydrogen fuel and expanded.

3. White Dwarf Stars:

Hot, compact remnants of stars that have shed their outer layers.

4. Neutron Stars:

Extremely dense, spinning stars formed from supernovae explosions.

5. Black Holes:

Regions of spacetime where gravity is so strong, not even light escapes.

6. Brown Dwarfs:

Objects that don’t quite meet the criteria for stars, as they don’t sustain nuclear fusion.

7. Variable Stars: Stars that change brightness, including:

Cepheid Variables (pulsating, used for distance measurement)
RR Lyrae Variables (pulsating, used for distance measurement)
Delta Scuti Variables (pulsating, rapid changes)
Mira Variables (long-period, pulsating)

8. Binary and Multiple Star Systems: Stars that orbit each other, including:

– Visual Binaries (visible with a telescope)
– Spectroscopic Binaries (detected by spectral changes)
– Eclipsing Binaries (stars pass in front of each other)

9. Supergiant Stars:

Extremely large, luminous stars, often near the end of their lives.

10. Wolf-Rayet Stars:

Massive, hot stars with strong winds and intense radiation.

In 2024 new discoveries and advancements in astronomy may lead to further divisions or reclassifications of star types.