Zeta Cancri

2 March 2021, 19:30 – 20:30

Seeing: Poor – average

Transparency: Very poor

A cool night with a soupy haze that developed into mist and then cloud over the course of the hour. Only the brightest stars were visible to the naked eye; the Beehive Cluster (usually a good indicator of transparency at this time of year) wasn’t even visible with averted vision. I wouldn’t normally take the telescope out under such below-par skies, but I wanted to test the plastic milk-jug fix for the azimuth stiction (verdict: it still needs some work), and it was also an opportunity to revisit Zeta Cancri, subject of Phil Harrington’s latest Cosmic Challenge on Cloudy Nights.

Starting with something familiar, Rigel was an easy split this evening, compared to 12 January. Sirius however was dancing and swimming and hard to keep in tight focus. I returned to it a couple of times and viewed it at both 171x and 240x, and once or twice I did get a glimpse of something possibly glinting in its wake, but not to the point where I could I say I was confident of the sighting.

Zeta Cancri is a lovely triple star comprised of two very close stars (currently 1.2” apart) and another bright star following behind at a more comfortable 5 arcseconds. When the variable seeing allowed, Zeta Cancri A and Zeta Cancri B were cleanly split at 240x. The split was also visible (if not quite so obvious) at 171x, which is probably more testament to the sharpness of the 7mm DeLite than my eyesight.

I also had a look at the Gemini twins: Castor, a very bright double star; and Pollux, not a double star, but showing a distinct tangerine hue.

Nature note:

At least a dozen frogs in the pond – some mating, some croaking – and several clumps of frogspawn.