Ad Astra
M☉ Notation
Unit of measurement in
astronomy called the solar mass.
- M stands for Mass
- ☉ Astronomical Symbol/Sun
- 1 M☉, Benchmark unit
- Equal to mass of our Sun
The Sun
(NASA/ESA)
Spirograph Nebula
(NASA/ESA)
Hourglass Nebula
(NASA/ESA)
A-Type Star
Star Classification: A
Luminosity Classification: V
Temperature (K) : 9000
Mass: 1.4–2.1 M☉ (main-sequence)
Elemental Composition: Hydrogen, Helium, iron, calcium
Description: White stars with strong hydrogen absorption lines and temperatures around 7,400-10,000 K.
Birth: Collapse of medium-large molecular clouds
Life: Bright white stars with strong hydrogen lines
☠️ Death: Expands into a red giant
Reincarnation: White dwarf
Example: Sirius A, Vega
Luminosity Classes
Added to spectral types.
Indicates size & brightness:
- 0 or Ia+: Hypergiants
- I (Ia, Ib): Supergiants
- II: Bright Giants
- III: Regular Giants
- IV:Subgiants
- V: Main Sequence
- VI (sd): Subdwarfs
- D (VII): White Dwarfs
Galaxy in Orange
(Wiki Images)
Wolf-Rayet Star
(NASA/ESA)
Planetary Nebula (PN K 4-55)
(NASA/ESA)
