Hubble Captures Blobs of Material Sweeping through Stellar Disk
These two NASA Hubble Space Telescope images, taken six years apart, show fast-moving blobs of material sweeping outwardly through a debris disk around the young, nearby red dwarf star AU Microscopii (AU Mic). Red dwarfs are the most abundant and longest-lived stars in our Milky Way galaxy. AU Mic is approximately 23 million years old.
The top image was taken in 2011; the bottom in 2017. Hubble's Space Telescope Imaging Spectrograph (STIS) took the images in visible light. This comparison of the two images shows the six-year movement of one of the known blobs (marked by an arrow). Researchers estimate that the blob, which is zipping along at nearly 15,000 miles an hour, traveled more that 820 million miles between 2011 and 2017. That is about the distance from Earth to Saturn. Astronomers do not know how the blobs are launched through the system.
Eventually, the blob highlighted in the image will sweep through the disk, escape the star's gravitational grip, and race out into space. Astronomers expect the string of blobs to clear out the disk within 1.5 million years. Their estimated ejection speeds are between 9,000 miles per hour and 27,000 miles per hour, fast enough to escape the star's gravitational clutches. They currently range in distance from roughly 930 million miles to more than 5.5 billion miles from the star.
The disk, seen edge-on, is illuminated by scattered light from the star. The glare of the star, located at the center of the disk, has been blocked out by the STIS coronagraph so that astronomers can see more structure in the disk. The bright dot above the left side of the disk in the 2017 image is a background star.
The system resides 32 light-years away in the southern constellation Microscopium.
Credits
NASA, ESA, J. Wisniewski (University of Oklahoma), C. Grady (Eureka Scientific), and G. Schneider (Steward Observatory)| About The Object | |
|---|---|
| Object Name | AU Mic, AU Micrscopii |
| Object Description | Debris Disk Around Nearby Star |
| R.A. Position | 20:45:9.49 |
| Dec. Position | -31:20:26.99 |
| Constellation | Microscopium |
| Distance | 32 light-years (9.79 parsecs) |
| About The Data | |
| Data Description | Hubble data for this release were obtained from HST proposal (G. Schneider) |
| Instrument | HST/STIS |
| Exposure Dates | 16 Jul 2011, 19 Oct 2017, 26 Jul 2018 |
| About The Image | |
| Color Info | These images are a composite of separate exposures acquired by the STIS instrument on the Hubble Space Telescope. The color results from assigning the color blue to a monochromatic (grayscale) image. |
| 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. |
