Astronomy Now Home
Home Magazine Resources Store

On Sale Now!

The October 2014 issue of Astronomy Now is on sale! Order direct from our store (free 1st class post & to UK addresses). Astronomy Now is the only astronomy magazine specially designed to be read on tablets and phones. Download the app from Google Play Store or the Apple App Store.

Top Stories

Earthshine used to test life detection method
...By imagining the Earth as an exoplanet, scientists observing our planet's reflected light on the Moon with ESO's Very Large Telescope have demonstrated a way to detect life on other worlds...

Solid buckyballs discovered in space
...Astronomers using NASA’s Spitzer Space Telescope have detected a particular type of molecule, given the nickname “buckyball”, in a solid form for the first time...

Steamy water-world gets the Hubble treatment
...Hubble Space Telescope observations of a 7 Earth-mass planet find an unusual water-rich world swathed in a thick, steamy atmosphere...

The Milky Way's
not-so-distant cousin


Posted: September 3, 2009

Bookmark and Share

A new image from the European Southern Observatory (ESO) reveals an edge-on galaxy much like our own Milky Way.

Seen edge-on, NGC 4945 appears much like our own Milky Way Galaxy. Sites of active star formation – HII regions – appear pink in this image. The field of view is 30 x 30 arcminutes; north is up and east is left. Image: ESO.

Taken with the Wide Field Imager (WFI) instrument on the 2.2 metre MPG/ESO telescope at the La Silla Observatory in Chile, the image of NGC 4945 reveals a spiral galaxy with swirling arms and a bar shaped central region resembling our home galaxy the Milky Way. But NGC 4945 has a brighter centre that likely hosts a supermassive black hole which is gorging on stellar matter and burping energy out into space.

Astronomers classify NGC 4945 as a Seyfert galaxy, after Ameriacn astronomer Carl Seyfert, who first identified this family of galaxies – a subclass of active galactic nuclei – to have curious light signatures emanating from their central engines. These emissions come from gas and dust falling into a disc around the black hole, which accelerates and heats it up until it emits high energy radiation such as X-rays and ultraviolet light. Most large spiral galaxies, including the Milky Way, host a black hole in their cores, though many of these monsters are at a stage of their lives where they no longer actively feed.

NGC 4945 resides 13 million light years from Earth in the constellation of Centaurus, and can be seen in modest amateur telescopes. It appears cigar-shaped from our perspective but it is actually many times wider than it is thick, with bands of stars and glowing gas marching around its centre. With the use of special optical filters to isolate the colour of light emitted by heated gases such as hydrogen, the new image from ESO displays sharp contrasts in NGC 4945 that indicate active areas of star formation.

The Planets
From tiny Mercury to distant Neptune and Pluto, The Planets profiles each of the Solar System's members in depth, featuring the latest imagery from space missions. The tallest mountains, the deepest canyons, the strongest winds, raging atmospheric storms, terrain studded with craters and vast worlds of ice are just some of the sights you'll see on this 100-page tour of the planets.

Hubble Reborn
Hubble Reborn takes the reader on a journey through the Universe with spectacular full-colour pictures of galaxies, nebulae, planets and stars as seen through Hubble's eyes, along the way telling the dramatic story of the space telescope, including interviews with key scientists and astronauts.

3D Universe
Witness the most awesome sights of the Universe as they were meant to be seen in this 100-page extravaganza of planets, galaxies and star-scapes, all in 3D!


© 2014 Pole Star Publications Ltd.