A New Angle on Two Spiral Galaxies for Hubble's 27th Birthday

Hubble Celebrates Its Anniversary with a Spectacular Pair of Galaxies

Article ID: 673259

Released: 20-Apr-2017 10:00 AM EDT

Source Newsroom: Space Telescope Science Institute (STScI)

  • Credit: NASA, ESA, and M. Mutchler (STScI)

    When the Hubble Space Telescope launched aboard the Space Shuttle Discovery on April 24, 1990, astronomers could only dream what they might see. Now, 27 years and more than a million observations later, the telescope delivers yet another magnificent view of the universe - this time, a striking pair of spiral galaxies much like our own Milky Way. These island cities of stars, which are approximately 55 million light- years away, give astronomers an idea of what our own galaxy would look like to an outside observer. The edge-on galaxy (at left) is called NGC 4302, and the tilted galaxy (at right) is NGC 4298. Although the pinwheel galaxies look quite different because they are angled at different positions on the sky, they are actually very similar in terms of their structure and contents.

  • Credit: NASA, ESA, and M. Mutchler (STScI)

    This is an infrared image of the galaxy pair NGC 4302 and NGC 4298 taken with Hubble's Wide Field Camera 3. The infrared light pierces through the dust lanes and shows significantly more stars than seen in visible light. In the infrared, the edge-on NGC 4302 is brighter than in the visible view. The tilted galaxy NGC 4298's spiral arms aren't as obvious in infrared, because the infrared light glows through the dust that marks the arms in visible light. This image represents the sort of view the James Webb Space Telescope will have when it is launched in late 2018. Webb's infrared vision will slice through dust to see the stars embedded in it.

  • Credit: NASA, ESA, and M. Mutchler (STScI)

    This is a Hubble Space Telescope view of a small, random location on the sky, awash largely with spiral galaxies like our Milky Way. This sea of galaxies stretches across billions of light-years. Most of the prominent galaxies look different only because they are tilted at various orientations to Earth, from edge-on to face-on. A few others are involved in mergers. The objects with diffraction spikes are foreground stars in our own galaxy. The image was taken with the Advanced Camera for Surveys (ACS) at the same time a much closer pair of spiral galaxies, NGC 4302 and NGC 4298, was being simultaneously photographed by Hubble's Wide Field Camera 3 (WFC3). These so-called "parallel field" observations increase the efficiency of how the telescope is used when making observations.

FOR RELEASE: 10:00 am (EDT) April 20, 2017



Newswise — In celebration of the 27th anniversary of the launch of NASA's Hubble Space Telescope on April 24, 1990, astronomers used the legendary telescope to take a portrait of a stunning pair of spiral galaxies. This starry pair offers a glimpse of what our Milky Way galaxy would look like to an outside observer.

The edge-on galaxy is called NGC 4302, and the tilted galaxy is NGC 4298. These galaxies look quite different because we see them angled at different positions on the sky. They are actually very similar in terms of their structure and contents.

From our view on Earth, researchers report an inclination of 90 degrees for NGC 4302, which is exactly edge on. NGC 4298 is tilted 70 degrees.

In NGC 4298, the telltale, pinwheel-like structure is visible, but it's not as prominent as in some other spiral galaxies. In the edge-on NGC 4302, dust in the disk is silhouetted against rich lanes of stars. Absorption by dust makes the galaxy appear darker and redder than its companion. A large blue patch appears to be a giant region of recent star formation.

Both galaxies are approximately 55 million light-years away. They reside in the constellation Coma Berenices in the Virgo Cluster of nearly 2,000 galaxies. Both were discovered in 1784 by astronomer William Herschel. Such objects were first simply called "spiral nebulas," because it wasn't known how far away they were. In the early 20th century, Edwin Hubble discovered that galaxies are other island cities of stars far outside our Milky Way.

A typical spiral galaxy has arms of young stars that wind outward from its center. The bright arms are regions of intense star formation. Such galaxies have a central bulge and are surrounded by a faint halo of stars. Many spiral galaxies also have bars that extend from the central bulge to the arms.

The edge-on NGC 4302 is about 87,000 light-years in diameter, which is about 60 percent the size of the Milky Way. It is about 110 billion solar masses, approximately one-tenth of the Milky Way's mass.

The tilted NGC 4298 is about 45,000 light-years in diameter, about one-third the size of the Milky Way. At 17 billion solar masses, it is less than 2 percent of the Milky Way galaxy's 1 trillion solar masses.

The Hubble observations were taken between January 2 and January 22, 2017, with the Wide Field Camera 3 (WFC3) instrument in three visible light bands.

The Hubble Space Telescope was launched aboard the Space Shuttle Discovery on April 24, 1990, and deployed into low-Earth orbit the next day. From its perch high above the distorting effects of Earth's atmosphere, Hubble observes the universe in near-ultraviolet, visible, and near-infrared light. Over the past 27 years, the space telescope's breakthrough discoveries have revolutionized the fields of astronomy and astrophysics.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

Credit: NASA, ESA, and M. Mutchler (STScI)

For more information about this galaxy pair and Hubble, visit:




Ann Jenkins / Ray Villard

Space Telescope Science Institute, Baltimore, Maryland

410-338-4488 / 410-338-4514

jenkins@stsci.edu / villard@stsci.edu


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