This sequence of 100 sec exposures taken with HST's Wide Field and Planetary Camera (WFPC2) in planetary mode on 10 August 1995 shows the newly discovered object 1995S5 (red arrows) moving in its orbit around the planet. As it moves further from Saturn, its brightness decreases appreciably. This brightness variation is more consistent with that expected for an elongated, opaque clump of ring material than for a satellite, leading to the suspicion that 1995S5 is in fact a ring arc rather than a previously undiscovered satellite. It is likely that it lies within the narrow, braided F Ring.
In addition to 1995S5, the larger satellites Mimas and Epimetheus are visible in each frame. Mimas is the bright object below the rings, and is seen partly shadowed by the rings in the first frame. In subsequent frames it is in full sunlight. Epimetheus is near the eastern ansa of the rings, moving slowly outward. In the last frame of the sequence tiny Pandora has emerged from Saturn's shadow about 2 arcsec from the planet's limb.
These images were obtained one to two hours before the Earth crossed Saturn's ring plane and an 8922 A methane band filter was used to reduce the scattered light from the planet. An average of several other frames has been subtracted from each image to remove the light from the edge-on rings, and so reveal any faint satellites.
Credits
Phil Nicholson (Cornell University), Mark Showalter (NASA-Ames/Stanford) and NASA| About The Object | |
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| Object Name | Saturn, 1995S5, Mimas, Epimetheus |
| About The Object | |
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| 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 |
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| 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. |
