The Night Sky May 2019
If you have followed these articles you may remember me writing about Ursa Major (The Plough). This is almost directly overhead and the end two stars famously point towards the North Star, Polaris. But very close to the handle of The Plough, in a region called Canes Venatici, is an object that was first discovered by Charles Messier in 1773. He was in fact looking for objects that might be confused with comets but instead saw something rather wonderful. To be exact - two things! Two galaxies, one much larger than the other locked together by gravity. Currently, it is thought that the two have either passed through each other or very close by, as the smaller galaxy has been distorted. The larger named the Whirlpool Galaxy, containing 100 billion stars, looks like water spinning and draining down an empty plug-hole, dragging its companion (M51b) with it. (See image) At the very centre of the ‘plug hole’ is thought to exist a black hole. This is a region so packed with matter in a very small space that its gravity will not let even light escape from it, therefore appearing black. The light that set off from the Whirlpool Galaxy, 23 million years ago, is that light we observe today. So we see it as it was then, millions of years ago, in effect looking way back in time.
Marathon Man
Charles Messier born in 1730 spent part of his life searching for comets. Whilst doing so, he made the most famous record of deep-sky objects. Often, in astronomical literature, some deep-sky objects are prefixed with an M eg M42 (The Orion Nebula) . These are from the Messier catalogue. The objects are based in order of when they were added to his list. Ironically, he made his list to discount annoying smudges in the sky that weren’t comets. You may want to see all 110 of them and this is possible with a modest telescope. He discovered them from a hotel rooftop in Paris so from Embsay’s beautiful dark sky you have a particularly good chance at different times during the year. There are specific dates during the year to see them all in one night and complete the Messier Marathon. This is certainly on the bucket list for me and many other amateur astronomers. The next possible opportunity will be March next year 2020. With a computerised system, a telescope will find each object with ease but not everyone has that luxury - so slowly does it and in the end over months or years (!) you will get through the list. Some of the objects are quite amazing, even one that looks like a big eye staring back at you! So here is your chance to start ticking them off. The Whirlpool (M51a) and on my diagram you can find 2 more very close by, The Sunflower Galaxy (M63) and The Cats Eye Galaxy (M94).
Planet Watch
The best time to view faint objects this month is 4th May (New Moon) and therefore no moonlight to drown your view. Planets to watch out for are Mars in the west which is slowly sinking. Below the horizon at midnight, on 7th , it will be just above the thin crescent of the moon. Look out for Mercury in the north-west towards the end of the month. It is many times brighter than Mars but sets after 10pm. Jupiter takes over the baton in the south-east as it rises at 11pm.
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