Magnitude +11.2 face-on spiral galaxy NGC 6814 lies in the constellation Aquila, 74.4 million light-years from Earth. Click the image for a full-size view. Image credit: ESA/Hubble & NASA. Acknowledgement: Judy Schmidt.Spiral galaxies together with irregular galaxies make up approximately 60 percent of the galaxies in the local Universe. However, despite their prevalence, each spiral galaxy is unique — like snowflakes, no two are alike. This is demonstrated by the striking face-on spiral galaxy NGC 6814, whose luminous nucleus and spectacular sweeping arms, rippled with an intricate pattern of dark dust, are captured in this NASA/ESA Hubble Space Telescope image.
NGC 6814 has an extremely bright nucleus, a telltale sign that the galaxy is a Seyfert galaxy. These galaxies have very active centres that can emit strong bursts of radiation. The luminous heart of NGC 6814 is a highly variable source of X-ray radiation, causing scientists to suspect that it hosts a supermassive black hole with a mass about 18 million times that of the Sun.
As NGC 6814 is a very active galaxy, many regions of ionised gas are studded along its spiral arms. In these large clouds of gas, a burst of star formation has recently taken place, forging the brilliant blue stars that are visible scattered throughout the galaxy.
Zooming in on black holes is the main mission for the newly installed GRAVITY instrument at ESO’s Very Large Telescope in Chile. During its first observations, GRAVITY successfully combined starlight using all four 1.8-metre Auxiliary Telescopes. The first observations using GRAVITY with the four 8-metre VLT Unit Telescopes are planned for later in 2016.
Some galaxies pump out vast amounts of energy from a very small volume of space, typically not much bigger than our own solar system. The cores of so-called active galactic nuclei (AGNs) can be billions of light-years away, so are difficult to study in any detail. However, natural gravitational ‘microlenses’ can provide a way to probe these objects.
This NASA/ESA Hubble Space Telescope image captures the glow of distant stars within NGC 5264, a dwarf galaxy located just over 15 million light-years away in the constellation of Hydra (The Sea Serpent). NGC 5264 clearly possesses an irregular shape — unlike the more common spiral or elliptical galaxies — with knots of blue star formation.
