Martin Mobberley ambles through the early evening constellations ofAquarius, Cetus and Pisces in search of some celestial novelties,

摘要

Tonight our starting point is south-western Aquarius,and an oft-forgottenglobular cluster.M720 is the faintestof Charles Messier's 28 globulars,simplybecause it lies so far from Earth at a locationin the galactic halo,55,000 light years away.At 6.6 arcminutes,M72 is also the smallestof the Messier globulars(despite being over100 light years wide in reality) but don'tlet that put you off observing it,althoughbeware that decent apertures will still onlyshow it as a grainy smudge. Resolving itsindividual magnitude+17 stars is only realisticwith a CCD camera.Nevertheless,if youcan find second magnitude beta(B Aquarii(Sadalsuud),you will discover M72 some11 degrees to that star's south-west,alreadytransiting as night falls.