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The Heart of the Whirlpool Galaxy
New images from NASA's Hubble Space Telescope are helping researchers view in unprecedented detail the spiral arms and dust clouds of a nearby galaxy, which are the birth sites of massive and luminous stars.
The Whirlpool galaxy, M51, has been one of the most photogenic galaxies in amateur and professional astronomy. Easily photographed and viewed by smaller telescopes, this celestial beauty is studied extensively in a range of wavelengths by large ground- and space-based observatories. This Hubble composite image shows visible starlight as well as light from the emission of glowing hydrogen, which is associated with the most luminous young stars in the spiral arms.
M51, also known as NGC 5194, is having a close encounter with a nearby companion galaxy, NGC 5195, just off the upper edge of this image. The companion's gravitational pull is triggering star formation in the main galaxy, as seen in brilliant detail by numerous, luminous clusters of young and energetic stars. The bright clusters are highlighted in red by their associated emission from glowing hydrogen gas.
This Wide Field Planetary Camera 2 image enables a research group, led by Nick Scoville (Caltech), to clearly define the structure of both the cold dust clouds and the hot hydrogen and link individual clusters to their parent dust clouds. Team members include M. Polletta (U. Geneva); S. Ewald and S. Stolovy (Caltech); R. Thompson and M. Rieke (U. of Arizona).
Intricate structure is also seen for the first time in the dust clouds. Along the spiral arms, dust "spurs" are seen branching out almost perpendicular to the main spiral arms. The regularity and large number of these features suggests to astronomers that previous models of "two-arm" spiral galaxies may need to be revisited. The new images also reveal a dust disk in the nucleus, which may provide fuel for a nuclear black hole.
The team is also studying this galaxy at near-infrared wavelengths with the NICMOS instrument onboard Hubble. At these wavelengths, the dusty clouds are more transparent and the true distribution of stars is more easily seen. In addition, regions of star formation that are obscured in the optical images are newly revealed in the near-infrared images.
This image was composed by the Hubble Heritage Team from Hubble archival data of M51 and is superimposed onto ground-based data taken by Travis Rector (NOAO) at the 0.9-meter telescope at the National Science Foundation's Kitt Peak National Observatory (NOAO/AURA) in Tucson, AZ.
About the Object
- R.A. PositionR.A. PositionRight ascension – analogous to longitude – is one component of an object's position.13h 29m 52.37s
- Dec. PositionDec. PositionDeclination – analogous to latitude – is one component of an object's position.+47° 11' 40.8"
- ConstellationConstellationOne of 88 recognized regions of the celestial sphere in which the object appears.Canes Venatici
- DistanceDistanceThe 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.About 9.6 Mpc (31 million light-years). Visual Magnitude: 8.4
- DimensionsDimensionsThe physical size of the object or the apparent angle it subtends on the sky.The image is roughly 9.3 kpc (30,000 light-years) in the vertical dimension.
About the Data
- Data DescriptionData DescriptionProposal: A description of the observations, their scientific justification, and the links to the data available in the science archive.
Science Team: The astronomers who planned the observations and analyzed the data. "PI" refers to the Principal Investigator.The release image of M51 was created from WFPC2 archived HST data from science programs by N. Scoville (Proposal 7375), H. Ford (Proposal 5123), and R. Kirshner (Proposal 5777). HST data have been superimposed onto BVRI and Ha ground-based data, taken by Travis Rector (NOAO) at the 0.9 meter telecope located on Kitt Peak, Tucson, AZ (NOAO/AURA/NSF). Ground-based Data: B, V, R, I, Ha 0.9-meter telescope KPNO (NOAO/AURA) Principal Astronomers: N. Scoville (Caltech), M. Polletta (U. Geneva), S. Ewald and S. Stolovy (Caltech), R.Thompson and M. Rieke (U. of Arizona), H. Ford (JHU), B. Margon (University of Washington), A. Davidsen (JHU), R. Bohlin (STScI), E. Beaver (UCSD), F. Bartko (Bartko Science & Technology), R. Harms (RJH Scientific, Inc.), R. Angel (University of Arizona), M. Burbidge (UCSD), R. Kirshner (Harvard University), N. Panagia (STScI), N. Suntzeff (NOAO/CTIO), B. Leibundgut (ESO Germany), A. Filippenko (UC Berkeley), C. Fransson (Stockholm University), J. Wheeler (U Texas Austin) - InstrumentInstrumentThe science instrument used to produce the data.HST>WFPC2
- Exposure DatesExposure DatesThe date(s) that the telescope made its observations and the total exposure time.January 15 - 24, 1995, and July 21, 1999, Exposure Time: 5.7 hours
- FiltersFiltersThe camera filters that were used in the science observations.Prop 7375: F439W (B), F555W (V), F656N (Ha), and F814W (I) Prop 5123: F547M (y), and F656N (Ha) Prop 5777: F439W (B), F555W (V), and F814W (I)
- Object NameObject NameA name or catalog number that astronomers use to identify an astronomical object.The Whirlpool Galaxy, M51, NGC 5194
- Object DescriptionObject DescriptionThe type of astronomical object.Face-on Spiral Galaxy with Companion
- Release DateApril 5, 2001
- Science ReleaseHubble Reveals the Heart of the Whirlpool Galaxy
- CreditNASA and The Hubble Heritage Team (STScI/AURA); Acknowledgment: N. Scoville (Caltech) and T. Rector (NOAO)
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Claire Andreoli
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
claire.andreoli@nasa.gov
