Your Night Sky for Sept. 23, 2020

Formalhaut the Fish

The first quarter moon will make the sky  to be easy to observe the stars and planets. The full moon is Oct. 1.  The moon will join up with Jupiter and be just below to the right. It joins up with Saturn and is just below it to the left. Both of those planets are still highly visible in the south just to the left of the Milky Way.


The bright star Formalhaut is now visible low in the southeast. It’s bright enough to be visible with the moon close by. It’s also called the Lonely One or the Solitary One, since that part of the sky doesn’t have other bright stars. Early in the evening it sits very low in the sky, but then it reaches its highest point by midnight.


Its constellation is a fish with it facing to the left, making Formalhaut its mouth since it sits on the left side of the Fish. Actually, the name Formalhaut means mouth of the fish. Since the other stars are very pale, you may not be able to see them without binoculars or a telescope. Our good thing is that since we live in the southern part of our state, we may be able to see it earlier in the evening and we may also be able to see the constellation.


Formalhaut is the eighteenth brightest star in our sky and is very bright white. It’s also called the Autumn Star since that’s when we can see it. The fish constellation is one of the 48 original constellations identified by Ptolemy. Sometimes the star actually twinkles blue, white or green.


It’s also the first star found with a visible exoplanet. In September it’s opposite our Sun in the sky, so it shines in the sky all night. But it’s always less than 1/3 of the way up in our sky. That’s why we have to look so low for it.


It’s classifies as an A3V star which means that it’s hotter and heavier than our Sun.  If they were close together it would outshine our Sun almost 17 times. But since its 25 LY away, we can’t see that it’s twice as large as our Sun.  So, when you go out to look at the sky before you go to bed, look low in the SE and see if you can find this star. Or if you get up during the night, then look out in the SE to see if you can find it.