Giants of the Milky Way: Top of the Most Massive, Largest, and Brightest Stars

The Most Massive Stars

The most massive stars are unstable colossi, born in very gas-rich stellar nurseries. Their mass, measured in solar masses (M☉), often exceeds 100 times that of the Sun. They lose a lot of mass through intense stellar winds. These stars are of spectral type O or Wolf-Rayet (WR) and live for a very short time, only a few million years, due to their frenzied consumption of nuclear fuel. Their end is often explosive, in the form of a Hypernova or Collapsar, giving birth to stellar black holes.

These stars play a crucial role in the evolution of galaxies and the enrichment of the interstellar medium with heavy elements. They produce heavy elements (carbon, oxygen, up to iron) by fusion and disperse them into space through their explosion.

• 1. R136a1 – ~215 M☉ – 163,000 ly (Large Magellanic Cloud) – Constellation Dorado
• 2. WR 102ka (Peony Nebula Star) – ~175 M☉ – 26,000 ly – Constellation Sagittarius
• 3. BAT99-98 – ~150 M☉ – 163,000 ly (Large Magellanic Cloud) – Constellation Dorado
• 4. R136c – ~140 M☉ – 163,000 ly (Large Magellanic Cloud) – Constellation Dorado
• 5. LBV 1806-20 – ~130 M☉ – 29,000 ly – Constellation Sagittarius
• 6. R136a2 – ~130 M☉ – 163,000 ly (Large Magellanic Cloud) – Constellation Dorado
• 7. NGC 3603-A1 – ~120 M☉ – 20,000 ly – Constellation Carina
• 8. HD 93129A – ~110 M☉ – 7,500 ly – Constellation Carina
• 9. WR 25 – ~100 M☉ – 7,500 ly – Constellation Carina
• 10. Eta Carinae – ~100 M☉ – 7,500 ly – Constellation Carina
• 11. WR 20a – ~83 M☉ (each component) – 20,000 ly – Constellation Carina
• 12. VFTS 682 – ~82 M☉ – 163,000 ly – Constellation Dorado

Note: Stars located at ~163,000 light-years are part of the Large Magellanic Cloud (satellite galaxy of the Milky Way) which is in the Constellation Dorado.

The Largest Stars

These stars are defined by their colossal radius, measured in solar radii (R☉). They are often Red Supergiants or Hypergiants, with atmospheres so diluted that their edge becomes blurry. If such a star replaced our Sun, its surface would encompass at least the orbit of Jupiter.

The largest stars end in a supernova (or hypernova), leaving behind a black hole or a neutron star. Some might even produce gamma-ray bursts during their collapse. These stars are cosmic monsters, but ephemeral, which play a key role in enriching the Universe with heavy elements before their spectacular disappearance.

• 1. UY Scuti – ~1700 R☉ – 9,500 ly – Scutum
• 2. RW Cephei – ~1650 R☉ – 11,500 ly – Cepheus
• 3. NML Cygni – ~1640 R☉ – 5,300 ly – Cygnus
• 4. V354 Cephei – ~1520 R☉ – 9,000 ly – Cepheus
• 5. WOH G64 – ~1540 R☉ – 163,000 ly (Large Magellanic Cloud) – Mensa (Magellanic Cloud)
• 6. VY Canis Majoris – ~1420 R☉ – 3,800 ly – Canis Major
• 7. KY Cygni – ~1420 R☉ – 5,000 ly – Cygnus
• 8. AH Scorpii – ~1411 R☉ – 3,300 ly – Scorpius
• 9. VX Sagittarii – ~1350 R☉ – 5,100 ly – Sagittarius
• 10. Mu Cephei – ~1260 R☉ – 6,000 ly – Cepheus
• 11. V838 Monocerotis – up to ~1570 R☉ – 20,000 ly – Monoceros
• 12. Betelgeuse – ~887 R☉ – 642 ly – Orion

The Brightest Stars

The luminosity of a star, measured in solar luminosity (L☉), depends on its temperature and size according to the Stefan-Boltzmann law. Some stars emit several million times the solar luminosity, dominated by type O stars and luminous blue variables (LBV). They represent a tiny fraction of stars (e.g., only 0.0001% of stars are type O).

• 1. R136a1 – ~8,700,000 L☉ – 163,000 ly (Large Magellanic Cloud) – Constellation: Dorado
• 2. Eta Carinae – ~5,000,000 L☉ – 7,500 ly – Constellation: Carina
• 3. WR 102ka – ~3,200,000 L☉ – 26,000 ly – Constellation: Sagittarius
• 4. R136c – ~3,000,000 L☉ – 163,000 ly – Constellation: Dorado
• 5. WR 25 – ~2,400,000 L☉ – 7,500 ly – Constellation: Carina
• 6. HD 93129A – ~2,500,000 L☉ – 7,500 ly – Constellation: Carina
• 7. VFTS 682 – ~2,100,000 L☉ – 163,000 ly (Large Magellanic Cloud) – Constellation: Dorado
• 8. NGC 3603-A1 – ~2,000,000 L☉ – 20,000 ly – Constellation: Carina
• 9. LBV 1806-20 – ~2,000,000 L☉ – 29,000 ly – Constellation: Sagittarius
• 10. BAT99-98 – ~1,800,000 L☉ – 163,000 ly (Large Magellanic Cloud) – Constellation: Dorado
• 11. WR 20a – ~1,700,000 L☉ – 20,000 ly – Constellation: Carina
• 12. HD 269810 – ~1,600,000 L☉ – 163,000 ly (Large Magellanic Cloud) – Constellation: Dorado