With 46 billion pixels, a 194 gigabyte file size and numerous stars, a massive new Milky Way photo has been assembled from astronomical observation data gathered over a five-year period.
Astronomers headed by Prof. Dr. Rolf Chini have been monitoring our Galaxy in a search for objects with variable brightness. The researchers explain that these phenomena may, for example, include stars in front of which a planet is passing, or may include multiple systems where stars orbit each other and where the systems may obscure each other at times. The researchers are analyzing how the brightness of stars changes over long stretches of time.
In his Ph.D. thesis, Moritz Hackstein is compiling a catalogue of such variable objects of medium brightness. Working toward this purpose, a research team from Ruhr-Universität Bochum’s Chair of Astrophysics takes pictures of the southern sky night after night. They use the telescopes at Bochum’s university observatory in the Atacama Desert in Chile (at the site selected for the European Extremely Large Telescope).
More than 50,000 new variable objects, which had not been previously recorded in databanks, have been discovered by the researchers to date. The area the astronomers are observing is so large that they have subdivided it into 268 sections, and they are photographing each section at intervals of several days. By comparing the images, the researchers are able to identify the variable objects.
The team has assembled the individual images of the 268 sections into one amazing comprehensive image. Following a calculation period of several weeks, they were able to create a 194 gigabyte file, into which images taken with different filters were entered. (The filters split the light of the stars into different wavelengths, which allows the researchers to determine whether something that is supposed to be a single star is really composed of several stars.)
Now, using an online tool, any interested person can
- view the complete ribbon of the Milky Way at a glance
- zoom in and inspect specific areas
- use an input window, which provides the position of the displayed image section, to search for specific objects. (i.e. if the user types in “Eta Carinae,” the tool moves to the respective star; entering the search term “M8” leads to the lagoon nebula.)
You can view the entire Milky Way photo at http://gds.astro.rub.de and read more on the search for variable objects at http://rubin.rub.de/en/sky-more-crowded-we-thought?.
- M. Hackstein et al. (2015): The Bochum Survey of the Southern Galactic Disk: II. Follow-up measurements and multi-filter photometry for 1323 square degrees monitored in 2010 – 2015, Astronomical Notes, DOI: 10.1002/asna.201512195
- M. Haas, M. Hackstein, M. Ramolla, H. Drass, R. Watermann, R. Lemke, R. Chini (2012): The Bochum survey of the southern Galactic disk: I. Survey design and first results on 50 square degrees monitored in 2011, Astronomical Notes, DOI: 10.1002/asna.201211717