In illustrations, Ara is usually depicted as compact classical altar with its smoke 'rising' southward. Johann Elert Bode's illustration of Ara, from his Uranographia (1801)
Within the constellation is Westerlund 1, a super star cluster that contains the red supergiant Westerlund 1-26, one of the largest stars known. The Milky Way crosses the northwestern part of Ara. Gliese 676 is a (gravity-paired) binary red dwarf system with four known planets. Sunlike Mu Arae hosts four known planets. Seven star systems are known to host planets.
The orange supergiant Beta Arae, to us its brightest star measured with near-constant apparent magnitude of 2.85, is marginally brighter than blue-white Alpha Arae. It was (as Βωμός, Bōmǒs) one of the Greek bulk (namely 48) described by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations designated by the International Astronomical Union. East is to the left and North to the top.Visible at latitudes between + 25° and − 90°.īest visible at 21:00 (9 p.m.) during the month of July.Īra ( Latin for "the Altar") is a southern constellation between Scorpius, Telescopium, Triangulum Australe, and Norma. The exposure time was 300 sec for each frame in H-alpha, and 60 sec in B and V. light rays of different colours are bent differently in air. This is due to the effect of differential atmospheric refraction, i.e. It may also be noted that there is a slight misalignment of the individual colours in stellar images at the extreme corners of the large field. Finally, the combined images in each filter are aligned and colour-coded to produce the colour picture.įor the processing of this large photo (8k x 8k 256 Mbytes), a minimum of contrast correction was made and very faint lines may still be perceived in some places where the individual frames were joined. This procedure is not simple, as the observing conditions may change slightly from exposure to exposure, resulting in small differences. The monochromatic images are then produced by superimposing the individual frames, correcting for the telescope offsets this ensures that the complete field is well covered. The images in each filter are the composite of 4 individual frames obtained with the telescope pointing at slightly different positions on the sky, so that the parts of the sky falling in the gaps between the 8 individual 2k x 4k CCDs in any given frame are recorded on the others. The blue component corresponds to the B filter, the green to the V filter, and the red to the H-alpha filter. This colour picture is a composite made from 12 separate images, obtained with the WFI on 27 March 1999. Still, it is very large, even in the highly compressed jpeg format, reflecting the great amount of details visible. The resolution in this image has been degraded by reducing the number of pixels in one direction from about 8000 to 3000 in the "High-Resolution version", in order to make the image transportable over the web without incurring completely unacceptable transfer times.
The photo shows the RCW 108 complex of bright and dark nebulae in the southern association Ara OB1, a star-forming region in the constellation Ara (the Altar), deep in the southern sky. Each frame records 8184 x 8196, or over 67 million, pixels in a sky field of 32 x 32 arcmin 2.
#THE EYES OF ARA SPACE PICTURE SERIES#
A series of images were obtained with the Wide Field Imager (WFI) of areas in the Milky Way band, including some in which interstellar nebulae of gas and dust are seen. RCW 108 is a molecular cloud that is in the process of being destroyed by intense ultraviolet radiation from heavy and hot stars in the nearby stellar cluster NGC 6193, seen to the left in the photo.
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