Left: This is an image of the star HR 8799 taken by Hubble's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) in 1998. A mask within the camera (coronagraph) blocks most of the light from the star. Astronomers also used software to digitally subtract more starlight. Nevertheless, scattered light from HR 8799 dominates the image, obscuring the four faint planets. The exoplanets were discovered in 2007, 2008, and 2010 in near-infrared ground-based images taken with the W.M. Keck Observatory in Hawaii and the Gemini North telescope in Chile. The system is 133 light-years from Earth.
Right: A re-analysis of NICMOS data in 2011 uncovered three of the exoplanets, which were not seen in the 1998 images. Sophisticated software processing of the NICMOS data removes most of the scattered starlight to reveal the three planets orbiting HR 8799. Astronomers used this decade-old image to calculate the planets’ orbits. The fourth, innermost planet cannot be seen because it is on the edge of the NICMOS coronagraphic spot that blocks the light from the central star.
Webb will probe the planets’ atmospheres at infrared wavelengths astronomers have rarely used to image distant worlds. Webb will also hunt for other distant worlds — possibly down to Saturn-size — on the outskirts of planetary systems that cannot be detected with ground-based telescopes.
Credits
Image
NASA, ESA, Rémi Soummer (STScI)
| About The Object | |
|---|---|
| Object Name | HR 8799 |
| Object Description | Star with planets |
| R.A. Position | 23h 7m 28.65s |
| Dec. Position | 21° 8' 3.69" |
| Constellation | Pegasus |
| Distance | 130 light-years or 40 parsecs |
| About The Data | |
| Data Description | The original NICMOS data were from the HST proposal : E. Becklin (University of California, Los Angeles) et al. The science team comprises: R. Soummer, B. Hagan, and A. Rajan (STScI), L. Pueyo and A. Thormann (JHU), and C. Marois (Herzberg Institute of Astrophysics, Victoria). |
| Instrument | HST>NICMOS/NIC2 |
| Exposure Dates | October 30, 1998, Exposure Time: 20 minutes |
| Filters | F160W |
| About The Image | |
| Color Info | This image was originally black and white and recorded only overall brightness. These brightness values were translated into a range of arbitrary colors. Such color "maps" can be useful in helping to distinguish subtly varying brightness in an image. |
| 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. |
