Far-Flung Supernova Sheds Light on Dark Universe

[Left] - A Hubble Space Telescope image of a portion of the Hubble Deep Field North as originally photographed in 1995 with the Wide Field Planetary Camera 2.

[Right] - A composite image of the same field as imaged by Hubble's Advanced Camera for Surveys (ACS), combined with the original WFPC2 image. The ACS observations were made in May and June 2002. The red spot is the glow of a very distant supernova captured exploding in the field. The supernova is estimated to be 8 billion light-years away. The supernova appears deep red in this composite image because it was photographed by the ACS at far-red wavelengths. Distant supernovae are used by astronomers to fill in the blank region where the universe's rate of expansion switched from deceleration due to gravity to acceleration due to the repulsive force of "dark energy."

About the colours

1995 image (left) Blue: F450W (B) Green: F606W (V) Red: F814W (I) 2002 image (right) Blue: F450W (B) Green: F606W (V) Red: F775W (SDSS i) + F850LP (SDSS z)

About the data

These observations are from the HST proposals: 9301 (H. Ford and collaborators) and 9352 (A. Riess (STScI) and collaborators).

The science team for the SN2002dd results include: J.P. Blakeslee (JHU), Z.I. Tsvetanov (JHU), A. Riess (STScI), H.C. Ford (JHU), G.D. Illingworth (UCO/Lick Obs.), D. Magee (Lick Obs./UCSC), J. Tonry (IfA/Univ. Hawaii), N. Benitez (JHU), M. Clampin (STScI), G.F. Hartig (STScI), G.R. Meurer (JHU), M. Sirianni (JHU), D.R. Ardila (JHU), F. Bartko (Bartko Science & Technology), R.J. Bouwens (UCO/Lick Obs.), T.J. Broadhurst (Racah Institute of Physics, The Hebrew University), N.J.G. Cross (JHU), P.D. Feldman (JHU), M. Franx (Leiden Observatory), D.A.Golimowski (JHU), C. Gronwall (PSU), R.A. Kimble (NASA GSFC), J.E. Krist (STScI), A.R. Martel (JHU), F. Menanteau (JHU), G.K. Miley (Leiden Obs.), M. Postman (STScI), P. Rosati (ESO), W.B. Sparks (STScI), L.-G. Strologer (STScI), H.D. Tran (JHU), R.L. White (STScI/JHU), and W. Zheng (JHU).