NASA's Spitzer Space Telescope recently captured these infrared images of six older stars with known planets. The yellow, fuzzy clouds are discs of dust, or "debris discs," like the one that surrounds our own Sun. Though astronomers had predicted that stars with planets would harbor debris discs, they could not detect such discs until now.
Spitzer was able to sense these dusty discs via their warm infrared glows. Specifically, the presence of the discs was inferred from an excess amount of infrared emission relative to what is emitted from the parent star alone.
The stars themselves are similar in age and temperature to our Sun. In astronomical terms, they are stellar main sequence stars, with spectral types of F, G, or K. These planet-bearing stars have a median age of four billion years. For reference, our Sun is classified as a G star, with an age of approximately five billion years.
The discs surrounding these planetary systems are comprised of cool material, with temperatures less than 100 Kelvin (-173 degrees Celsius). They are 10 times farther away from their parent stars than Earth is from the Sun, and are thought to be analogues of the comet-filled Kuiper Belt in our solar system.
The contrast scale is the same for each image. The images are approximately 2 arcminutes on each side. North is oriented upward and east is to the left. The pictures were taken with the 70-micron filter of Spitzer's multiband imaging photometer. The telescope resolution at 70 microns is 17 arcseconds and there is no evidence for any emission extended beyond the telescope resolution.
Credits
NASA/JPL-Caltech/C. Beichman (Caltech)| About The Object | |
|---|---|
| Object Name | Top row (left to right): HD 117176, HD 33636, HD 52265 Bottom row (left to right): HD 82943, HD 50554, HD 128311 |
| Object Description | Stars with Debris Disks |
| R.A. Position | 20h 45m 9.53s |
| Dec. Position | -31° 20' 27.19" |
| About The Data | |
| Instrument | SST>MIPS |
| Filters | 24 and 70 um |
| 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. |
