Color differences could recalibrate cosmic acceleration rate
Two flavors of Type 1a supernovas complicate distance estimates
![the M101 galaxy](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2015/04/cc_supernovabrief_free.jpg?fit=860%2C460&ssl=1)
STAR BRIGHT Color differences between some nearby supernovas, such as the one shown here (arrow) in this image of the M101 galaxy about 22 million light-years away, and ones farther away could lead to overestimates of how much the cosmic expansion is accelerating.
Swift/NASA