Hubble Finds Andromeda Star Formation Fell to 0.2 Solar Masses a Year Over 500 Million Years
Updated
Updated · Universe Today · Aug 14
Hubble Finds Andromeda Star Formation Fell to 0.2 Solar Masses a Year Over 500 Million Years
3 articles · Updated · Universe Today · Aug 14
Summary
Hubble data show Andromeda’s star formation has slowed to about one-fifth of a solar mass per year, down from roughly one solar mass 500 million years ago and half that by 40 million years ago.
Two Hubble surveys — PHAT and PHAST — mapped about two-thirds of the galaxy’s disk and resolved roughly 190 million stars, letting researchers reconstruct star-formation histories in thousands of 300-light-year regions.
Much of the remaining recent star birth is concentrated in a ring about 32,000 light-years from Andromeda’s center, indicating the broader decline is being driven by fading activity in that structure.
The team says the slowdown likely reflects a natural wind-down after a more active era, though a possible interaction with satellite galaxy M32 remains under scrutiny after star formation between the two galaxies also weakened about 60 million years ago.
Andromeda, 2.5 million light-years away and home to about 1 trillion stars, is a key Milky Way analog; NASA’s Roman Space Telescope is expected to map its full disk with a field of view at least 100 times Hubble’s.