Probing the Last Gasps of the Doomed Star Eta Carinae
About This Image
Release Date
September 09, 2009 11:00AM (EDT)Read the Release
2009-25Permissions
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Caption
The signature balloon-shaped clouds of gas blown from a pair of massive stars called Eta Carinae have tantalized astronomers for decades. Eta Carinae has a volatile temperament, prone to violent outbursts over the past 200 years.
Observations by the newly repaired Space Telescope Imaging Spectrograph (STIS) aboard NASA's Hubble Space Telescope reveal a stream of charged particles from a massive stellar wind and some of the chemical elements that were ejected in the eruption seen in the middle of the nineteenth century.
STIS resolved the chemical information along a narrow section of one of the giant lobes of ejected material. In the resulting spectrum, iron and nickel define the outer material cast off in the nineteenth century from Eta Carinae. STIS also reveals the interior material being carried away by the ongoing wind from Eta Car A, the primary star. The amount of mass being carried away by the wind is the equivalent of one sun every thousand years.
While this "mass loss" may not sound very large, in fact it is an enormous rate among stars of all types. A very faint structure, seen in argon, is evidence of an interaction between winds from Eta Car A and those of Eta Car B, the hotter, less massive, secondary star.
Eta Car A is one of the most massive and most visible stars in the sky. Because of the star's extremely high mass, it is unstable and uses its fuel very quickly, compared to other stars. Such massive stars also have a short lifetime, and astronomers expect that Eta Carinae will explode within a million years.
Eta Carinae was first catalogued by Edmund Halley in 1677. In 1843 Eta Carinae was one of the brightest stars in the sky. It then slowly faded until, in 1868, it became invisible in the sky. Eta Carinae started to brighten again in the 1990s and was again visible to the naked eye. Around 1998 and 1999 its brightness suddenly and unexpectedly doubled.
Eta Carinae is 7,500 light-years away in the constellation Carina.
The Hubble observations are part of the Hubble Servicing Mission 4 Early Release Observations. NASA astronauts repaired STIS during a servicing mission in May to upgrade and repair the 19-year-old Hubble telescope.
Credits
NASA, ESA, and the Hubble SM4 ERO TeamKeywords
| About The Object | |
|---|---|
| Object Name | Eta Carinae, Eta Car |
| Object Description | Variable Star |
| R.A. Position | 10h 45m 3.59s |
| Dec. Position | -59° 41' 4.26" |
| Constellation | Carina |
| Distance | 7,500 light-years (2,300 parsecs) |
| Dimensions | This image is 0.6 arcminutes (1.2 light-years or 0.4 parsecs) wide. |
| About The Data | |
| Data Description | The Hubble images were created from data from proposals 11500: K. Noll (STScI) and 11506: K. Noll (STScI), B. Woodgate (NASA/GSFC), C. Proffitt (STScI/CSC), and T. Gull (NASA/GSFC). Acknowledgments for Eta Car Observers: K. Noll (STScI), B. Woodgate (NASA/GSFC), C. Proffitt (STScI/CSC), and T. Gull (NASA/GSFC) Data Analysis: M. Mutchler (STScI) Image Composition: Z. Levay and L. Frattare (STScI) Text: D. Weaver and R. Villard (STScI) Illustrations: Z. Levay (STScI) Video: G. Bacon (STScI) Science Consultants: M. Livio (STScI) and T. Gull (NASA/GSFC) |
| Instrument | HST>WFPC2 (left), HST>STIS/CCD (spectra) |
| Exposure Dates | September 5-6, 2008, Exposure Time: 38 minutes (WFC2), and June 29-30, 2009, Exposure Time: 28 minutes (spectra) |
| Filters | WFPC2: F336W (U), F502N ([O III]), F631N ([O I]), F656N (H-alpha), and F658N ([N II]) STIS/CCD: G430M (430nm) and G750M (750nm) |
| About The Image | |
| Color Info | The WFPC2 image is a composite of separate exposures made by the WFPC2 instrument on the Hubble Space Telescope. Five filters were used to sample narrow wavelength ranges. The color results from assigning different hues (colors) to each monochromatic image. In this case, the assigned colors are: Red: F658N ([N II]) Yellow: F656N (H-alpha) Green: F631N ([O I]) Cyan: F502N ([O III]) Blue: F336W (U) |
| 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 |
|
| 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. |