STIS Reveals Invisible High-Speed Collision Around Supernova 1987a

 STIS Reveals Invisible High-Speed Collision Around Supernova 1987a

The highest velocity material expelled in a cataclysmic stellar explosion ten years ago has been detected for the first time by the Hubble Space Telescope's Space Telescope Imaging Spectrograph (STIS).

The top image, taken with Hubble's Wide Field and Planetary Camera 2 in 1995, shows the orange-red rings surrounding Supernova 1987A in the Large Magellanic Cloud. The glowing debris of the supernova explosion, which occurred in February 1987, is at the center of the inner ring. The small white square indicates the location of the STIS aperture used for the new far-ultraviolet observation.

The STIS spectrograph viewed the entire inner ring in far-ultraviolet light, spreading it into a spectrum. The Earth's atmosphere completely blocks ultraviolet radiation from reaching the Earth's surface, hence astronomers can study the ultraviolet universe only from orbiting telescopes. The dark square in this image is where the spectrum was processed to remove the emission from hydrogen in the Earth's outer atmosphere.

The STIS data in the middle panel (and a schematic representation in the bottom panel) shows the presence of glowing hydrogen expanding at a speed of 33 million miles per hour (15,000 kilometers per second) coming from an extended area inside the inner ring. In addition to hydrogen emission STIS also detected emission from high-velocity ionized nitrogen.

This is the first time that astronomers have measured the very fast moving gas ejected by the supernova explosion, which was invisible until observed by Hubble with the STIS ultraviolet detectors. This gas is glowing in the ultraviolet because it is slamming into the remains of the gas lost by the supernova star about 20,000 years before it exploded.

The STIS spectrum also reveals the presence of emissions from hot gasses (oxygen, nitrogen, and helium) coming from the inner ring itself. The ring is about 1.2 light-years in diameter.

Supernova 1987A is located 167,000 light-years from Earth in the Large Magellanic Cloud.

Credits

Image

NASA, George Sonneborn (NASA-GSFC), Jason Pun (NOAO), Peter Challis (CfA), STIS IDT Team, SINS Collaboration

About The Object
Object Name SN 1987A
R.A. Position 05h 35m 28.25s
Dec. Position -69° 16' 13.0"
About The Object
Object Name A name or catalog number that astronomers use to identify an astronomical object.
Object Description The type of astronomical object.
R.A. Position Right ascension – analogous to longitude – is one component of an object's position.
Dec. Position Declination – analogous to latitude – is one component of an object's position.
Constellation One of 88 recognized regions of the celestial sphere in which the object appears.
Distance The 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.
Dimensions The physical size of the object or the apparent angle it subtends on the sky.
About The Data
Data Description
  • Proposal: 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.
Instrument The science instrument used to produce the data.
Exposure Dates The date(s) that the telescope made its observations and the total exposure time.
Filters The camera filters that were used in the science observations.
About The Image
Image Credit The primary individuals and institutions responsible for the content.
Publication Date The date and time the release content became public.
Color Info A brief description of the methods used to convert telescope data into the color image being presented.
Orientation The rotation of the image on the sky with respect to the north pole of the celestial sphere.