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Galaxy NGC 2403: Before and After Supernova 2004dj Outburst

The image at left represents a small region of NGC 2403, a galaxy located 11 million light-years from Earth. The photo was taken two months before a massive star exploded. The image pinpoints the location of the stellar blast, known as supernova 2004dj, within a cluster of massive, generally blue (but some red) stars called Sandage 96. The cluster's total mass is estimated at about 24,000 times the mass of the Sun. The stars in this cluster are so far away that their light blends together, appearing as the light of a single star. The yellow object below and to the left of the cluster is a foreground star in our Milky Way Galaxy. The pink blob at bottom, center is a star-birth region. This image was taken May 8, 2004, with the WIYN 0.9-meter mosaic camera at Kitt Peak National Observatory in Arizona.
The image at right pinpoints the supernova blast. The photo was taken on Aug. 17, 2004, with the Hubble Space Telescope's Advanced Camera for Surveys. The light from this outburst outshines every star in the massive cluster. Similar blue clusters of stars can be seen throughout the image. The bluish-pink blob towards the bottom of the image is a large star-birth region.
About the Object
- R.A. PositionR.A. PositionRight ascension – analogous to longitude – is one component of an object's position.07h 36m 57.22s
- Dec. PositionDec. PositionDeclination – analogous to latitude – is one component of an object's position.65° 36' 21.53"
- ConstellationConstellationOne of 88 recognized regions of the celestial sphere in which the object appears.Camelopardalis
- DistanceDistanceThe physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs.Approximately 11 million light-years (3.4 Megaparsecs)
About the Data
- Data DescriptionData DescriptionProposal: A description of the observations, their scientific justification, and the links to the data available in the science archive.
Science Team: The astronomers who planned the observations and analyzed the data. "PI" refers to the Principal Investigator.This image was created from HST data from proposal 10182: A. V. Filippenko (UC Berkeley), P. Challis (Harvard-Smithsonian CfA) and collaborators. - InstrumentInstrumentThe science instrument used to produce the data.WIYN>0.9m Mosaic (left) and HST>ACS/WFC (right)
- Exposure DatesExposure DatesThe date(s) that the telescope made its observations and the total exposure time.May 8, 2004 (WIYN), August 17, 2004 (ACS)
- Object NameObject NameA name or catalog number that astronomers use to identify an astronomical object.SN 2004dj, NGC 2403
- Object DescriptionObject DescriptionThe type of astronomical object.Supernova in spiral galaxy
- Release DateSeptember 2, 2004
- Science ReleaseA Bright Supernova in the Nearby Galaxy NGC 2403
- Credits
Related Images & Videos
A Bright Supernova in the Nearby Galaxy NGC 2403
The explosion of a massive star blazes with the light of 200 million Suns in this NASA Hubble Space Telescope image. The arrow at top right points to the stellar blast, called a supernova. The supernova is so bright in this image that it easily could be mistaken for a foreground...

NGC 2403: Annotated Hubble View
This detailed view of spiral galaxy NGC 2403 shows the location of Supernova 2004dj, numerous star clusters, and several other stars that exploded in previous years. The region was observed with the Hubble Space Telescope's Advanced Camera for Surveys on Aug. 17, 2004.

NGC 2403: Ground-based and Hubble View
This composite image shows a ground-based image of NGC 2403 and the location of a 10,000 light-year-wide square region imaged with the Hubble Space Telescope's Advanced Camera for Surveys. The area is host to Supernova 2004dj, the closest explosion of a massive star in over a...
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Claire Andreoli
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
claire.andreoli@nasa.gov