Hubble shows star formation in Andromeda galaxy is winding down

A new study published in The Astrophysical Journal, using data from NASA’s Hubble Space Telescope, has found that star formation in the nearby Andromeda galaxy has declined over the past 500 million years.

• The study indicates that the decline has become particularly steep during the last 40 million years.
• Andromeda, also known as Messier 31 (M31), is a spiral galaxy comparable in size to the Milky Way.
• Located approximately 2.5 million light-years from Earth, Andromeda is close enough to be visible to the unaided eye from areas with dark skies.
• Its relative proximity provides astronomers with an opportunity to study its stellar populations in detail, helping scientists better understand the evolution of galaxies like the Milky Way.

Decline in Star Formation

• Previous research indicates that Andromeda experienced a dramatic burst of star formation around 2 billion years ago.
• This burst was likely triggered by a past interaction or merger with another galaxy.
• Following this event, the rate of star formation in Andromeda has steadily declined.
• Astronomers measure the star formation rate based on the amount of gas and dust converted into new stars per year.
• According to the study:
  • Around 500 million years ago, Andromeda formed stars at a rate of approximately one solar mass per year.
  • By 40 million years ago, the rate had declined to approximately half a solar mass per year.
  • The present rate has fallen further to approximately one-fifth of the Sun’s mass per year.

About Andromeda

• Andromeda is the closest major spiral galaxy to the Milky Way, making it an important laboratory for studying galactic structure and evolution.
• Studying Andromeda helps astronomers understand the history of the Milky Way, which is difficult to study from the inside because Earth is located within our own galaxy.
• Andromeda has also played an important role in the study of dark matter.
• In the 1960s, astronomer Vera Rubin and her colleagues studied the rotation of Andromeda and its spiral arms.
• Their observations indicated that unseen matter was influencing the movement of material within the galaxy.
• This unidentified material later became known as dark matter.

Source: TH & NASA