How will the recent appearance of a supernova, the closest in 27 years, help reduce the uncertainties in our measurements of dark energy? A supernova has been recently spotted on M82, also known as the cigar galaxy. Being the closest to earth in 27 years and given the advances of technology this article proposes that: 


  ...as the Cigar Galaxy has been studied in detail thanks to images from the Hubble Space Telescope. "It is likely that the star that blew up has been directly imaged"...
  
  If astronomers do find the dying star in past images and are able to make accurate readings of its brightness before and after the explosion, we might be able to reduce the uncertainties in our measurements of dark energy by a factor of two.


How will it help reduce the uncertainty?. Furthermore, how would this help us better understand the way the universe is going to end?.
The current supernova is a supernova of type Ia. Supernovae of type Ia are used as standard candles for distance estimates, especially used to determine the Hubble constant. Hence by a better calibration of this kind of supernovae, more about the reliability and accuracy of distance estimates can be learned.

The expansion rate (in relation to the distance) of the universe, expressed by the Hubble constant, is an important incredient for the estimation of the fate of the universe.