A Neptune-size planet with a clear atmosphere is shown crossing in front of its star in this artist's depiction. Such crossings, or transits, are observed by telescopes like NASA's Hubble and Spitzer to glean information about planets' atmospheres. As starlight passes through a planet's atmosphere, atoms and molecules absorb light at certain wavelengths, blocking it from the telescope's view. The more light a planet blocks, the larger the planet appears. By analyzing the amount of light blocked by the planet at different wavelengths, researchers can determine which molecules make up the atmosphere.
The problem with this technique is that sometimes planets have thick clouds that block any light from coming through, hiding the signature of the molecules in the atmosphere. This is particularly true of the handful of Neptune-sized and super-Earth planets examined to date, all of which appear to be cloudy.
As a result, astronomers were elated to find clear skies on a Neptune-sized planet called HAT-P-11b, as illustrated here. Without clouds to block their view, they were able to identify water vapor molecules in the planet's atmosphere. The blue rim of the planet in this image is due to scattered light, while the orange rim on the part of the planet in front of the star indicates the region where water vapor was detected.
Credits
NASA, ESA, and R. Hurt (JPL-Caltech)| About The Object | |
|---|---|
| Object Name | HAT-P-11b |
| Object Description | Neptune-size planet outside our solar system (exoplanet) |
| R.A. Position | 19h 50m 50s.25 |
| Dec. Position | +48° 04' 51".08 |
| Constellation | Cygnus |
| Distance | 120 light-years (37 parsecs) |
| About The Data | |
| Data Description | Note: Observations from NASA's Kepler Mission and Spitzer Space Telescope contributed to the discovery of HAT-P-11b. Hubble data for this release of HAT-P-11b were obtained from the following HST proposal: : D. Deming (University of Maryland, College Park, and NASA Ames/Astrobiology Institute), H. Knutson (Caltech), N. Madhusudhan (University of Cambridge/Institute of Astronomy), and K. Todorov (ETH Zurich). The science team comprises: J. Fraine (University of Maryland, College Park, Institute of Astrophysics/Pontificia Universidad Católica de Chile, and Caltech), D. Deming (University of Maryland, College Park, and NASA Ames/Astrobiology Institute), B. Benneke and H. Knutson (Caltech), A. Jordan and N. Espinoza (Institute of Astrophysics/Pontificia Universidad Católica de Chile), N. Madhusudhan (University of Cambridge/Institute of Astronomy), A. Wilkins (University of Maryland, College Park), and K. Todorov (ETH Zurich). |
| Instrument | HST>WFC3/IR |
| Exposure Dates | October 18, 2012, and December 15/16, 2012 |
| Filters | Grating: G141 |
| 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. |
