Hubble Space Telescope: Calling on a Galactic Neighbor

This image from the NASAEstablished in 1958, the National Aeronautics and Space Administration (NASA) is an independent agency of the United States Federal Government that succeeded the National Advisory Committee for Aeronautics (NACA). It is responsible for the civilian space program, as well as aeronautics and aerospace research. Its vision is "To discover and expand knowledge for the benefit of humanity." Its core values are "safety, integrity, teamwork, excellence, and inclusion." NASA conducts research, develops technology and launches missions to explore and study Earth, the solar system, and the universe beyond. It also works to advance the state of knowledge in a wide range of scientific fields, including Earth and space science, planetary science, astrophysics, and heliophysics, and it collaborates with private companies and international partners to achieve its goals.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>NASA/ESA Hubble Space TelescopeThe Hubble Space Telescope (often referred to as Hubble or HST) is one of NASA's Great Observatories and was launched into low Earth orbit in 1990. It is one of the largest and most versatile space telescopes in use and features a 2.4-meter mirror and four main instruments that observe in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. It was named after astronomer Edwin Hubble.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>Hubble Space Telescope features the galaxy LEDA 48062 in the constellation Perseus. LEDA 48062 is the faint, sparse, amorphous galaxy on the right side of this image, and it is accompanied by a more sharply defined neighbor on the left, the large, disc-like lenticular galaxy UGC 8603. A smattering of more distant galaxies also litter the background, and a handful of foreground stars are also visible throughout the image.

Have you ever wondered why the stars in Hubble images are surrounded by four sharp points? These are called diffraction spikes, and are created when starlight diffracts — or spreads around — the support structures inside reflecting telescopes like Hubble. The four spikes are due to the four thin vanes supporting Hubble’s secondary mirror and are only noticeable for bright objects like stars where a lot of light is concentrated on one spot. Darker, more spread-out objects like the galaxies LEDA 48062 and UGC 8603 do not possess visible diffraction spikes.

Hubble recently spent some time with our galactic neighbors. LEDA 48062 is only around 30 million light-years from the Milky WayThe Milky Way is the galaxy that contains our Solar System, and is named for its appearance from Earth. It is a barred spiral galaxy that contains an estimated 100-400 billion stars and has a diameter between 150,000 and 200,000 light-years.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>Milky Way, and was therefore included in the observing campaign Every Known Nearby Galaxy. The aim of this campaign was to observe precisely that: every known galaxy within 10 megaparsecs (around 33 million light-years) of the Milky Way. By getting to know our galactic neighbors, astronomers can determine what types of stars reside in various galaxies and also map out the local structure of the Universe.