AAQ Visual Observing Section

Selected Deep Sky Objects In Hydra

This month we shall stay in the north to check out the largest and longest constellation in the sky. Thanks again to Tim for his reporting of the double stars that are highlighted with this different text. Tim uses a 14” SCT and an 8” reflector for his reports. All my observations are made with a 150mm. F8 refractor. Also, just a reminder that I use “Sky Atlas 2000” and “Hartung’s Astronomical Objects for Southern Telescopes” for these articles.

M48 (RA. 08h 13.8m Dec. -05° 48) You will need a wide field eyepiece or even binoculars for this large open cluster. I could see this pretty grouping as a “V” shape with a chain of stars looping through the middle. Look for a delicate fainter pair visible near the centre of this loop.
Agreed; lovely, with many lines of stars (8”, dark sky observation).

BU 1421/ F Hydrae / S 579 (RA. 08h 44.0m Dec. -07° 15) mags. 4.7 & 8.2, sep. 79”, pa. 311° (2002). Set in an attractive star field, this very easy pair has a good colour combination of yellow primary and blue/green secondary. Agreed (8”, dark sky observation).

HJ 99 (RA. 08h 38.1m Dec. -06° 50) mags. 6.8 & 8.3, sep. 60.2”, pa. 181° (2002). Not far from BU 1421 is this very similar albeit fainter pair. In the same field of view you should be able to see another fainter delicate double. Lovely field at 137x in the 14”; 9-ish stars in a V-shape. Fainter double has a 3rd faint star at the apex of a triangle.

Struve 1270 (RA. 08h 45.4m Dec. -02° 37) mags. 6.9 & 7.5, sep. 4.7”, pa. 264° (2003). Look for the slight colour difference between this pair, I could just split them with 40x, and clear resolution with 80x. Definite in the 8” at 98x, maybe at 61x.

BU 587 / 15 Hydrae (RA. 08h 51.5m Dec. -07° 12) mag 5.8 & 7.4, sep. 1.1”, pa 121° (2003). Through a larger scope this is a four star system, with the primary component having a close companion. With 320x I could comfortably see the other two fainter members with magnitudes of 9.7 & 10.8 and separations of 45.7” & 54.7” and pa 5° and 56° respectively. The close pair (1.1”) split in the 14” at x556, though easier at x1668.

Struve 1295 / 17 Hydrae (RA. 08h 55.5m Dec. -08° 00) mag. 6.7 & 6.9, sep. 4.1”, pa 4° (2003). While just visible with 80x, 120x needed for good separation. Both components are of similar magnitude. Split at 98x though easier at 191x (8”, dark sky observation).

Tau / HJ 1167 (RA. 09h 29.3m Dec. -02° 48) mag. 4.6 & 7.3, sep. 66.2” pa. 5° (2002). A fine sight
set in an attractive star field with 40x. Easy wide bright pair. Primary pale lemon yellow, secondary pale blue.

BU 590 / 29 Hydrae (RA. 09h 27.3m Dec. -09° 15) mag. 7.8 & 11.3, sep. 10.7”, pa. 171° (1999). Easily found located close to Alphard / Alpha Hydrae, but I could not see the secondary. The 14” showed it with 237x; highish powers needed to provide contrast to see the dim secondary. Not visible in the 8” in a dark sky.

NGC 3242 (RA. 10h 24.8m Dec. -18° 38) With a magnitude of 7.7 this is a beautiful prominent
planetary nebula even with last quarter moonlight, one of the best I have seen. Easily found with 40x, there was a hint of it even with my finderscope. Using 80x seemed to give the best view, showing a ghostly, glowing compact ball of light set in a fine star field. Little wonder its popular name is “Ghost of Jupiter”. Agreed. Astonishingly bright, even in the suburbs with the 8”.

Struve 1474 (RA. 10h 47.6m Dec. -15° 18) mags. 7.5 & 7.8, sep. 6.7”, pa. 17° (1998). Bright stars either side makes this a prominent pair clearly resolved with 80x. This is actually a three star system, with the slightly brighter primary (mag.6.7) being just north east of the close (6.7”) pair of secondaries. In the same FOV you should see a slightly fainter and much wider double (Struve 1473) – look for the nice colour contrast with this second pair. Nice attractive field. Close double (6.7”) split with 61x (8”, dark sky observation).

NGC 3621 (RA. 11h 18.3m Dec. -32° 49) Situated in a barren area of the sky with no bright stars
close by, I found this galaxy a little difficult to find by the star hopping method. However at magnitude 8.9, it is well worth the effort. With 80x you should see a large conspicuous glow bordered by a trapezium of four faint stars. When using 120x and averted vision I could see an elongated central region. Need low magnification for brightness; seemed to be a dark vertical bar to one side of the central section (Sky Atlas 2000 says “knotty arms”) (8”, dark sky observation).

H 3 96 / N Hydrae (RA. 11h 32.4m Dec. -29° 18) mag. 5.6 & 5.7, sep. 9.4”, pa. 210° (2003). 40x reveals a fine sight, with two very similar magnitude components. Look for the off white/cream colour of the two components. Easy at 47x in the 8”.

HJ 4465 (RA. 11h 42.0m Dec. -32° 32) mag 5.2 & 8.3, sep. 66.1”, pa 44° (1999). The pale yellow
primary and blue/grey secondary make a stunning pair easily seen with 40x. Great contrast. Yellow-orange primary and blue secondary (14”).

NGC 3923 (RA. 11h 51.0m Dec. -28° 48) This magnitude 9.6 galaxy was clearly seen with 80x, and showed a slightly elongated shape. Just inside the same FOV you should be able to see it’s slightly fainter (mag. 10.8) companion galaxy NGC 3904.

Dunlop 116 (RA. 11h 57.0m Dec. -32° 18) mag. 7.7 & 7.8, sep. 18.9”, pa. 82° (1999). An easy pair with 40x, both similar magnitude components forming part of a triangular asterism of stars. Very nice field. 3rd much fainter (11.4?) star same distance N of the primary (14”).

HJ 4495 (RA. 12h 06.3m Dec.-33° 00) mag. 6.7 & 8.8, sep. 5.8”, pa. 319° (1999). Use 120x to look for a delicate yellow coloured pair. Very pretty and clear at 98x (8”, dark sky observation).

NGC 4105 / 6 (RA. 12h 06.7m Dec. -29° 46) These two companion interacting galaxies are very close together, and combined appear to cover a smaller area than NGC 3621. At magnitude 10.6 they are quite faint, but 80x and averted vision clearly showed the bright centres. Two very close spots of light, almost star-like; real star close by (8”, dark sky observation).

M68 (RA. 12h 39.5m Dec. -26° 47) Even with last quarter moonlight this magnitude 7.3 globular cluster is reasonably prominent. With 80x I could see hints of individual stars. Would be a good dark sky object.

HN 69 (RA. 13h 36.8m Dec. -26° 30) mags. 5.8 & 6.7, sep. 10.1”, pa 191°. Situated in a “Y” shaped asterism of fainter stars you will find this beautiful pair, easily seen with 40x. Look for the striking colour contrast between the two components. Easy at 47x in the 8”; both look white to me!

NGC 5694 (RA. 14h 39.6m Dec. -26° 32) This faint (mag. 10.2) globular was not visible in my finder, however it was reasonably easy to find, forming one corner of a trapezium of brighter stars. 80x showed a small faint glow, this is an object which requires a bigger scope, and a dark sky.

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