The Sun

1
The Suns Crowded Delivery Room
Moon

• Telescopic observations suggest that stars, even
  isolated ones like the Sun, form in clusters
• Meteorite studies can test this idea and give
  additional information about events leading to
  formation of the Solar System

Cluster of new stars in the constellation of Vela
(Courtesy of European Southern Observatory)
2
The Suns Crowded Delivery Room

• Precise analyses by Martin Bizzarro and his
  colleagues show that Earth, Mars, and chondritic
  meteorites contain evidence for the presence of
  60Fe (given by the 0.0 value of e60Ni, the decay
  product of 60Fe)
• In contrast, differentiated meteorites, which
  formed 1 My after initial solar system formation,
  have no evidence for 60Fe (low e60Ni)

3
The Suns Crowded Delivery Room

• In spite of having had no 60Fe, differentiated
  meteorites did contain 26Al, as did most early
  solar system materials
• Martin Bizzarro and his colleagues suggest
• 26Al was incorporated into the interstellar cloud
  that gave birth to the Sun when massive stars
  spewed strong stellar winds
• 60Fe was added a million years later when a
  massive star exploded

Wolf-Rayet star --
Stellar winds blowing from a massive Wolf-Rayet
star (brightest star near center) in NGC 2359
Nebula. Courtesy of P. Berlind P. Challis,
Harvard-Smithsonian Center for Astrophysics.