Starcast 4 of 2021. Middle to end February.
Last time I told you about asterisms These are patterns made by the stars that are either within a single constellation, or cut across several constellations. Examples known to most are:
1. Orion’s belt ( in Orion)
2. The Southern Cross ( in Crux)
3. The False Cross ( in Vela)
4. The Seven Sisters ( In Taurus)
This weeks project is to find five asterisms.
Looking northwest, Mars shining (or reflecting) bright orange is your marker. Move right along the same altitude above the horizon and you find yourself in the large constellation of Taurus. The Pleiades star cluster should be visible ( seven sisters) It is technically an asterism. The Japanese refer to it as Subaru, and hence the starry logo of that vehicle.
Look one outstretched hand width above and right. Your second asterism, still located in Taurus is “the V” or, face of the Bull.
Now, (after 10pm), turn to face east. The bright star low on the horizon is Regulus. This is in the constellation of Leo. But, see how Regulus makes up the the base of the handle of “The Sickle”.
This sickle is the mane of Leo, although for us in the southern hemisphere, it’s an upside down lion.
Now turn to face South. Low to the horizon is the asterism we all know as the Southern Cross, but if you look just a little higher in the band of the Milky Way, you see the “False Cross”.
To find your fifth target, look overhead. You’re looking for the “Great Triangle”. Find the brightest star in sky (Sirius). Now trace a line down towards the eastern horizon and the next bright star ( Procyon). From here move left and up towards Orion’s “bottom right” star Betelgeuse. Its unmistakable because, as a red giant, it shines orange.
You can seen how useful asterisms can be in navigating the sky. Instead of saying “22 degrees above the eastern horizon at 10pm on 15 Feb”, you just say ” just right of the sickle”.
(BTW. you may ask why we didn’t look west. At normal February night viewing times, west is located away from the galactic plane at and is very sparsely populated.)
There will be fairly good earthshine on the moon just after dusk on 15 Feb.
On 19 Feb the moon will be in conjunction with Subaru, making a good photographic opportunity. On 20 Feb the moon will be in “the V”.
On 26 Feb you’ll find the moon in your third asterism – “the Sickle”.
The following night is full moon, and rising at 19h40 pm and setting at 06h00 am, will keep you howling all night.
For the yogaists, dont miss the tennis court session on 25 Feb for almost maximum lunar energy ( aka a good hard workout).
Cheers till March.