Resembling comets streaking across the sky, these four speedy stars are plowing through regions of dense interstellar gas and creating brilliant arrowhead structures and trailing tails of glowing gas.
These bright arrowheads, or bow shocks, can be seen in these four images taken with NASA's Hubble Space Telescope. The bow shocks form when the stars' powerful stellar winds, streams of matter flowing from the stars, slam into surrounding dense gas. The phenomenon is similar to that seen when a speeding boat pushes through water on a lake.
The stars in these images are among 14 runaway stars spotted by Hubble's Advanced Camera for Surveys. The stars appear to be young, just millions of years old. Their ages are based on their colors and the presence of strong stellar winds, a signature of youthful stars.
Depending on their distance from Earth, the bullet-nosed bow shocks could be 100 billion to a trillion miles wide (the equivalent of 17 to 170 solar system diameters, measured out to Neptune's orbit). The bow shocks indicate that the stars are moving fast, more than 112,000 miles an hour (more than 180,000 kilometers an hour) with respect to the dense gas they are plowing through. They are traveling roughly five times faster than typical young stars, relative to their surroundings.
The high-speed stars have traveled far from their birth places. Assuming their youthful phase lasts only a million years and they are moving at roughly 112,000 miles an hour, the stars have journeyed 160 light-years.
The Hubble observations were taken between October 2005 and July 2006.
Credits
NASA, ESA, and R. Sahai (NASA's Jet Propulsion Laboratory)| About The Object | |
|---|---|
| Object Description | Stellar Bow Shocks |
| About The Data | |
| Data Description | Science Team: These images were created from HST archival data. The science team is led by R. Sahai (NASA/Jet Propulsion Laboratory; HST Archival Proposal ). |
| Instrument | HST>ACS |
| Exposure Dates | October 2005 and July 2006 |
| Filters | F606W (V) and F814W (I) |
| 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. |
