AAQ RESOLUTION SURVEY Observing Double Stars
PDF print version (202KB) I 240 (RA 15 36.2 Dec. -65 07) mags. 7.2 & 10.8, sep. 2.5”, pa 187˚ (1991). Quite hard with large magnitude difference and close. RMK 20 (Hartung 708) (RA. 15 47.9 Dec.-65 27) mags. 6.2 & 6.4, sep. 1.8”, pa. 147˚ (1991). Similar magnitudes; good direct test of resolution. HJ 4813 (RA. 15 55.5 Dec. -60 11) mags. 5.9 & 8.4, sep. 4.4”, pa.100˚ (2000). Magnitude difference of 2.5 but sufficient separation to be resolvable in most scopes. HDS 2352 (RA 16 37.8 Dec -64 15) mags. 7.7 & 10.3, sep. 10.9”, pa 148˚ (2000). Should be easy despite the faint secondary. HDO 257 (RA 16 46.7 Dec -67 07) mags. 5.1 & 11.5, sep. 25.0”, pa 123˚ (1900). This is testing the limiting magnitude of your scope and conditions. And its an interesting one. There are two secondaries of similar magnitudes close to each other; the one we want is probably the closer of the two and I think the brighter, so if you see either then count it as a hit. The two measures in the records are 30” at pa 180˚ (1891) and 25” at pa 123˚ (1900). My measure of the closer one is 28.5” at pa 194˚, so there may be some confusion of identity in the historical measures; it is unlikely to have moved 57˚ in 9 years so I think at least the 123˚ is wrong. Finder Chart for the Test Doubles in Triangulum Australe
Eyepiece Finder Charts for Triangulum Australe Note: The left hand chart has a 5°(finder) field of view, with stars shown to approx. magnitude 7. The right hand chart has a 1° (eyepiece) field of view, with stars shown to approx. magnitude 10. The target star is on the cross hairs at the centre of the image. North is up and East to the left, to conform to the view through a finder, refractor or a simple Newtonian without a star diagonal; turn them to orient north and south to conform to your view through the finder or ‘scope. If you are using an SCT or finder with a star diagonal, the E-W directions will be reversed.
RA 08 29.1 Dec. -47 56 This is a pretty triplet but concentrate on the close double. Should be visible in most ‘scopes. R87 Vel (Hartung 368) 4.9 7.7 2.6” 335 0 (1998) RA 08 56.3 Dec. -52 43 Nearly two magnitudes difference. h 4188 (Hartung 381) 6.0 6.8 2.8” 281 0 (1992) RA 09 12.5 Dec. -43 37 A direct test of resolution with two very similar magnitude stars. See 118 Vel (Hartung 410) 6.7 12.0 15.2” 142 0 (1934) RA 10 15.1 Dec. -55 33 This tests the limiting magnitude of the ‘scope and conditions. |
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