AAQ Visual Observing Section

Selected Deep Sky Objects In Grus

While continuing with the avian theme again this month, I thought we would spend some time away from the Milky Way. Grus is easy to find high in the south east, and somewhat unusually it even looks a little like the animal it is meant to represent. Because of the outline of prominent stars, finding the objects listed below using the starhopping method is relatively easy. All observations were made with a 150mm f/8 refractor.

Dunlop 246 or Δ246 (23h 07.2m RA, -50 ° 41' Dec) This very pretty pair of similar magnitudes (6.3 & 7.0) is easily split with 40x. Nearby you will find an easy blue/yellow pair of unequal magnitude, these appear of slightly wider separation than Δ246. A pretty triangle of stars is nearby, with the double star at the apex easily split with 40x, but the other double unresolved.

Not far from Δ246 is another easy pair (23h 24.0m RA, -53° 50' Dec) clearly split with 40x. This beautiful double has a yellow primary with a blue secondary star of similar magnitude.

Beta Grucis A double nearby (22h 45.3m RA, -47 ° 00' Dec) has a much fainter secondary with quite a wide separation, but its fainter magnitude makes it quite difficult to see – a larger telescope should help.

Theta Grucis (23h 06.9m RA, -43 ° 31' Dec) Try this double out, but with a separation of 1.3” it is well beyond my scope’s ability. Also try Sigma 2 and Upsilon, I was unable to resolve these too.

Pi 1 & Pi 2 Grucis (22h 22.9m RA, -45 ° 56' Dec) Like nearby Beta, the faint secondary stars of these two doubles were unresolved through my telescope – another good test for a larger instrument. While there, see if you can locate the nearby faint galaxy IC 5201.

NGC 7496 (23h 09.8m RA, -43 ° 26' Dec) I was able to glimpse this galaxy near Theta Grucis with 40x. Increasing the magnitude did not improve the view, as the contrast seemed to diminish. Try it yourself, the atmospheric seeing may have affected my attempts.

NGC 7552, NGC 7582, NGC 7590 & NGC 7599 (23h 16.2m RA, -42 ° 35' Dec) Use a wide field eyepiece here and you will be rewarded with these 4 galaxies visible in the same impressive field of view. With 40x I found 7582 the brightest, without doubt these would be a fine sight either photographically or through a larger telescope.

NGC 7410 (22h 55.0m RA, -39 ° 40' Dec) Whilst reasonably easy with 40x, increasing to 120x clearly shows the elongated shape of this galaxy, complete with a brighter central core.

IC 1459, NGC 7418 & NGC 7421 (22h 56.6m RA, -37 ° 02' Dec) This is another group of galaxies visible with 40x, with IC 4519 showing a brighter core with 120x.

For those who enjoy hunting “faint fuzzies”, this constellation will give you plenty to track down, with over 30 galaxies shown in Sky Atlas 2000.0

In conjunction with “Sky Atlas 2000.0” I use “Hartung’s Astronomical Objects for Southern Telescopes” as an excellent source of information on objects visible to the amateur scope. If you don’t have a copy for your own use, the AAQ library has one available, or it can usually be found for sale at the various telescope retailers.

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