In celebration of the 25th anniversary of NASA's first astronaut mission to service the Hubble Space Telescope in orbit, a comparison photo is being released today showing one of Hubble's first targets after its 1993 optical repair.
[RIGHT] - This photogenic celestial object, the magnificent spiral galaxy M100, is seen here as observed with Hubble's Wide Field Camera 3. Hubble's newest camera, it was installed during the last space shuttle servicing mission to Hubble in May 2009, and the M100 photo was taken a few months later. M100 is designated a grand-design spiral galaxy because of its two prominent lanes of young, blue stars. This is caused by ripples of matter in the stellar disk that propagate through the galaxy and create high-density regions of gas. These denser areas precipitate new star formation. In addition, clearly visible are two tightly wound, inner spiral arms wrapping around the core where there is a small bar pattern of stars. The yellowish color of the inner region is from older populations of stars.
[LEFT] - For comparison, this is a 1993 image of M100 taken with Hubble's Wide Field/Planetary Camera 1, which was part of an original suite of instruments launched aboard Hubble in 1990. Because of a manufacturing flaw in the primary mirror, which created an optical effect called spherical aberration, the galaxy appears blurred because it cannot be brought into a single focus. In particular, the orange foreground star below image center has tentacle-like image artifacts that are clear evidence of spherical aberration, where the starlight is not concentrated into a single point.
The same galaxy was re-photographed with the Wide Field/Planetary Camera 2, which was installed during the December 1993 space shuttle servicing mission (SM1, STS-61). The replacement camera contained corrective optics to compensate for the space telescope’s fuzzy view. Like putting contact lenses on a nearsighted patient, the M100 picture snapped into focus and was a stunning demonstration that Hubble had been returned to its expected sharpness. The M100 photo was just a preview of what was to come in subsequent servicing missions, which further improved Hubble’s capabilities. Hubble has enthralled the public with evocative and breathtaking pictures of the universe that have become even more stunning since that very first servicing mission.
Credits
NASA, ESA, and Judy Schmidt| About The Object | |
|---|---|
| Object Name | M100 |
| Object Description | Spiral galaxy |
| R.A. Position | 12:22:54.94 |
| Dec. Position | 15:49:19.49 |
| Constellation | Coma Berenices |
| Distance | 55 million light-years |
| Dimensions | Image is 2.7 arcmin across (about 43,000 light-years) |
| About The Data | |
| Data Description | The HST observations include those from programs , (W. Sparks) and (A. Crotts) |
| Instrument | WFPC1, WFPC2, WFC3/UVIS |
| Exposure Dates | Nov, Dec 1993, Jan 1994, and Nov 2009 |
| Filters | WFPC1: F439W, F555W, F702W, WFPC2: F439W, F555W, F702W, WFC3: F475W, F555W, F775W |
| About The Image | |
| Color Info | These images are a composite of separate exposures acquired by the WFPC1, WFPC2 and WFC3 instruments on the Hubble Space Telescope. Several filters were used to sample narrow wavelength ranges. 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: Blue: F439W and F475W Green: F555W Red: F702W and F775W |
| 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. |
