1 min read
Hubble’s View of Barred Spiral Galaxy NGC 1672
This NASA Hubble Space Telescope view of the nearby barred spiral galaxy NGC 1672 unveils details in the galaxy's star-forming clouds and dark bands of interstellar dust.
One of the most striking features is the dust lanes that extend away from the nucleus and follow the inner edges of the galaxy's spiral arms. Clusters of hot young blue stars form along the spiral arms and ionize surrounding clouds of hydrogen gas that glow red. Delicate curtains of dust partially obscure and redden the light of the stars behind them by scattering blue light.
Galaxies lying behind NGC 1672 give the illusion they are embedded in the foreground galaxy, even though they are really much farther away. They also appear reddened as they shine through NGC 1672's dust. A few bright foreground stars inside our own Milky Way Galaxy appear in the image as bright and diamond-like objects.
As a prototypical barred spiral galaxy, NGC 1672 differs from normal spiral galaxies, in that the arms do not twist all the way into the center. Instead, they are attached to the two ends of a straight bar of stars enclosing the nucleus. Viewed nearly face on, NGC 1672 shows intense star formation regions especially off in the ends of its central bar.
Astronomers believe that barred spirals have a unique mechanism that channels gas from the disk inward towards the nucleus. This allows the bar portion of the galaxy to serve as an area of new star generation.
NGC 1672 is also classified as a Seyfert galaxy. Seyferts are a subset of galaxies with active nuclei. The energy output of these nuclei can sometimes outshine their host galaxies. This activity is powered by accretion onto supermassive black holes.
NGC 1672 is more than 60 million light-years away in the direction of the southern constellation Dorado. These observations of NGC 1672 were taken with Hubble's Advanced Camera for Surveys in August of 2005. The composite image was made by using filters that isolate light from the blue, green, and infrared portions of the spectrum, as well as emission from ionized hydrogen.
About the Object
- R.A. PositionR.A. PositionRight ascension – analogous to longitude – is one component of an object's position.04h 45m 42s.10
- Dec. PositionDec. PositionDeclination – analogous to latitude – is one component of an object's position.-59° 14' 56"
- ConstellationConstellationOne of 88 recognized regions of the celestial sphere in which the object appears.Dorado
- 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.Approximately 60 million light-years (18 megaparsecs) away.
- DimensionsDimensionsThe physical size of the object or the apparent angle it subtends on the sky.This image is 4.4 arcminutes (75,000 light-years or 23 kiloparsecs) wide.
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 Hubble image was created from HST data from proposal 10354: L. Jenkins (University of Leicester), M. Ward and T. Roberts (University of Durham), A. Levan (University of Hertfordshire), and A. Zezas (Harvard- Smithsonian Center for Astrophysics). - InstrumentInstrumentThe science instrument used to produce the data.HST>ACS/WFC
- Exposure DatesExposure DatesThe date(s) that the telescope made its observations and the total exposure time.August 1, 2005, Exposure Time: 2.7 hours
- FiltersFiltersThe camera filters that were used in the science observations.F435W (B), F550M (y), F658N (Halpha+[N II]), and F814W (I)
- Object NameObject NameA name or catalog number that astronomers use to identify an astronomical object.NGC 1672
- Object DescriptionObject DescriptionThe type of astronomical object.Barred Spiral Galaxy
- Release DateApril 3, 2007
- Science ReleaseHubble’s View of Barred Spiral Galaxy NGC 1672
- Credit
This image is a composite of many separate exposures made by the ACS instrument on the Hubble Space Telescope using several different filters. Three filters were used to sample broad wavelength ranges. One filter was used to sample narrow wavelength emission. The color results from assigning different hues (colors) to each monochromatic image. In this case, the assigned colors are: Blue: F435W (B) Green: F550M (y) Red: F658N (Halpha+[N II]) + F814W (I)
Share
Details
Claire Andreoli
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
claire.andreoli@nasa.gov
