Hawaiian Astronomical Society

Constellations: Grus -- Observing the time of its Coming

Myth

Johann Bayer carved Grus, the Crane out of the constellation of Pisces Australis. Philippus Caesius' (Philip Zesen in the original Dutch) Coelum Stellatum Christianum (1627) called the the constellation the "Stork." This was based on a passage from Old Testament book of Jeremiah: "All of them turn to their own course, like a horse plunging headlong into battle. Even the stork in the heavens knows its times; and the turtledove, swallow, and crane observe the time of their coming; but my people do not know the ordinance of the LORD." Jeremiah 8:6b-7 (NRSV)

Caesius co-authored the book with Bayer and Julius Schiller (1759 - 1805), using Bayer's Uranometria as its model. Caesius died before the book could be completed, and Schiller saw the book through to publication, making a few changes as he went along. It seems he is responsible for some of the more far fetched Christian constellations. Grus might be one of them. Why call this region of sky the "stork," when the same biblical passage mentions the crane?

You can find good illustrations Caesius' and Schiller's work here.

Maps

Each map can be clicked on to produce a 929x1200 version of it. They sport red labels, which look good on screen, but which disappear when used with red flashlights. Each map, therefore has a second link to a map better suited for printing in a graphics program, and using in the field. While they are quite large, they are all about 50k, and so are easy to view at today's modem speeds. The first map is a wide area view of the constellation, suitable for naked eye browsing. The next views are binocular width, showing stars to mag. 10, deepsky objects to mag. 12.9, and labeling deepsky objects to magnitude 12.

Interactive, wide area map of Grus

Click the map for a 929x1200 version of the above. Click here for a map better suited for use in the field.

Detailed View

This a more detailed view of the constellation. The map displays stars to magnitude 10, and deepsky objects to magnitude 12. Click here for a map better suited for use in the field.

Images

28k JPEG NGC7410 (Bennett 129a) is a spiral galaxy located in north-western Grus, 4.5° WNW of Theta Gruis. Dreyer call it quite bright (mag. 11.5), large (5.3'x1.6'), very moderately extended (p.a. 43°, with a much brighter middle. A 4" will show its elongation.

Map

Printable Map

More info.

Image thumbnail 42k JPEG Four rather dim galaxies inhabit this area of northern Grus near the border of Pisces Austrinus and Sculptor. Here are their descriptions from north to south:
IC1459 (Bennett 129b) is described as faint (mag. 10) and fairly small (5.3'x3.8'). It looks much like a comet, complete with 12th magnitude nucleus. IC5264 sits 6.5' south of IC 1459. Shining at mag. 13.4 (photographic), and covering 2.5'x.5' of sky, this edge on galaxy (p.a. 82°) looks faint in a 13".
NGC7418 is a face on spiral galaxy described as quite bright (mag. 11.4), very large (2'x1.8'), very little extended, very gradually brightening a little toward the middle. It lies 28' south of IC5264. NGC7421 sits 19' south of NGC7418. It shines at mag. 12.7 and covers (2.0'x1.8'). Dreyer calls it quite bright, large, very little extended, gradually westward much brighter middle, and resolvable. Dreyer may have been a tad optimistic.
And if you are a glutton for punishment, NGC7418a, shining at mag. 14, lies just north of NGC7418. Good luck.

Map Printable Map

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