Comparison images from the Hubble Space Telescope, taken several years apart, have uncovered two eerie shadows moving counterclockwise across a gas-and-dust disk encircling the young star TW Hydrae. The disks are tilted face-on to Earth and so give astronomers a bird's-eye view of what's happening around the star. The left image, taken in 2016, shows just one shadow [A] at the 11:00 o'clock position. This shadow is cast by an inner disk that is slightly inclined to the outer disk and so blocks starlight. The picture on the left shows a second shadow that emerged from yet another nested disk [C] at the 7:00 o’clock position, as photographed in 2021. The original inner disk is marked [B] in this later view. The shadows rotate around the star at different rates like the hands on a clock. They are evidence for two unseen planets that have pulled dust into their orbits. This makes them slightly inclined to each other. This is a visible-light photo taken with the Space Telescope Imaging Spectrograph. Artificial color, to enhance details, has been added.
Credits
Image
NASA, ESA, STScI, John Debes (AURA/STScI for ESA)
Image Processing
Joseph DePasquale (STScI)
| About The Object | |
|---|---|
| Object Name | TW Hydrae |
| Object Description | Face-on protoplanetary disk around a T Tauri star |
| R.A. Position | 11:01:51.9054 |
| Dec. Position | -34:42:17.0316 |
| Constellation | Hydra |
| Distance | 196 light-years |
| Dimensions | Each image is 6.14 arcsec across, about 0.005 light-years |
| About The Data | |
| Data Description | The HST observations include those from program (J. Debes) |
| Instrument | STIS/MIRVIS |
| Exposure Dates | June 7, 2021 |
| Filters | MIRVIS |
| About The Image | |
| Color Info | The images are separate exposures acquired by the STIS instrument on the Hubble Space Telescope. The color results from assigning an orange hue to a monochromatic (grayscale) 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. |
