January Skynotes: Eridanus, a neglected winter constellation
These notes are taken from Christopher Taylor's observations of Eridanus over the years, all using the McIver Paton telescope. Click the images for larger versions.
From: Christopher T.
Sent: 03 March 2013 15:58
To: HCO.
Subject: LAST NIGHT.
Dear All,
A good session at the telescope last night, something which doesn’t happen all that often at our monthly HCO meetings. The mirror of the 30-inch is still in the w’shop at Walthamstow but should be back v. shortly; in its absence, we had some good views in the 12.5-inch in quite a good , if not superlative, sky: Jupiter+moons set very prettily in a starry field in the midst of the Hyades at low power, the ‘Great’ ‘Red’ Spot clearly visible almost on the centre-line of the disk at x238 in quite decent definition; an attractive but little-known colour-contrasted double star 32 Eridani, from the list of such circulated a while back; a very interesting triple-star system omicron-2 Eridani, a true 3-body system, whose second star is the only white dwarf EASILY visible in a telescope and whose third is an even dimmer red dwarf, all clearly visible at x238; one of the brighter planetaries, NGC 1535 Eridani, a small fuzz-ball quickly glimpsed in x75 wide-angle (only, as about to disappear behind western trees - this does show a lot more in the 12.5-inch at higher power); Rigel + Rigel B, the opposite extreme to omicron Eri. in the stellar ‘zoo’, a nice view at x238 - so within a few minutes at the eyepiece we had ranged from omicron Eri. C at 0.0008 of solar luminosity to Rigel at 40,000 solar, a ratio of 50 million: 1 in stellar brightness!; and finally, Orion’s Great Nebula*, a churning mass of primordial chaos at x238. This part of the heavens is truly an astrophysicist’s paradise.
For those who may be interested in extreme astronomy/astrophysics, see the entry in ‘Burnham’s Handbook’ for omicron Eridani and its famous white dwarf.
Yours randomly, Christopher.
* (Note added Jan. 2016): see next month’s Skynotes for more Hanwell obs. of M42 Orionis.