Looking like an apparition rising from whitecaps of interstellar foam, the iconic Horsehead Nebula has graced astronomy books ever since its discovery over a century ago. The nebula is a favorite target for amateur and professional astronomers.
In this new Hubble Space Telescope view, the nebula appears in a new light, as seen in infrared wavelengths. The nebula, shadowy in optical light, appears transparent and ethereal when seen in the infrared, represented here with visible shades. The rich tapestry of the Horsehead Nebula pops out against the backdrop of Milky Way stars and distant galaxies that are easily seen in infrared light.
The Horsehead was photographed in celebration of the 23rd anniversary of the launch of Hubble aboard the space shuttle Discovery. Over its two decades of producing ground-breaking science, Hubble has benefited from a slew of upgrades, including the 2009 addition of a new imaging workhorse: the high-resolution Wide Field Camera 3 that was used to take this portrait of the Horsehead.
The backlit wisps along the Horsehead's upper ridge are being illuminated by Sigma Orionis, a young five-star system just off the top of the Hubble image. A harsh ultraviolet glare from one of these bright stars is slowly evaporating the nebula. Along the nebula's top ridge, two fledgling stars peek out from their now-exposed nurseries.
Gas clouds surrounding the Horsehead have already dissipated, but the tip of the jutting pillar contains a slightly higher density of hydrogen and helium, laced with dust. This casts a shadow that protects material behind it from being photo-evaporated, and a pillar structure forms. Astronomers estimate that the Horsehead formation has about five million years left before it too disintegrates.
The Horsehead Nebula is part of a much larger complex in the constellation Orion. Known collectively as the Orion Molecular Cloud, it also houses other famous objects such as the Great Orion Nebula (M42), the Flame Nebula, and Barnard's Loop. At about 1,500 light-years away, this complex is one of the nearest and most easily photographed regions in which massive stars are being formed.
Hubble's pairing of infrared sensitivity and unparalleled resolution offers a tantalizing hint of what the upcoming James Webb Space Telescope, set for launch in 2018, will be able to do.
Credits
NASA, ESA, and the Hubble Heritage Team (STScI/AURA)| About The Object | |
|---|---|
| Object Name | Horsehead Nebula, Barnard 33 |
| Object Description | Dark Nebula; Dimensions: 5.75 arcminutes (2.5 light-years or 0.8 parsecs) wide. |
| R.A. Position | 05h 40m 58.99s |
| Dec. Position | -2° 27' 29.88" |
| Constellation | Orion |
| Distance | 1,600 light-years (490 parsecs) |
| About The Data | |
| Data Description | The image was created from Hubble data from proposal : Hubble Heritage Team: PI: Z. Levay, J. Mack, J. Sokol, T. Borders, M. Mutchler, W. Januszewski, M. Livio, C. Christian, and L. Frattare (STScI); and K. Noll (NASA/GSFC). |
| Instrument | HST>WFC3/IR |
| Exposure Dates | October 22, 2012 - November 7, 2012 |
| Filters | F110W (YJ) and F160W (H) |
| About The Image | |
| Color Info | This image is a composite of separate exposures acquired by the WFC3/IR instruments. Two filters were used to sample different infrared wavelength bands. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are: Cyan/blue: F110W (YJ) Red/orange: F160W (H) |
| Compass 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. |
