Classroom Aid - Sextans A
Channel: David Butler
Date: 2020-07-24

Text - http://howfarawayisit.com/wp-content/uploads/2020/07/Andromeda-and-the-Local-Group-2020.pdf

In this segment of our “How far away is it” video book, we cover the Andromeda galaxy along with our local group of galaxies, including some of the dwarf galaxies orbiting the Milky Way.

We begin with Edwin Hubble’s discovery of a Cepheid variable star in what was thought to be a Milky Way nebula. The star was V1 and it changed the history of astronomy. We also take a deep dive into the galaxy’s disk, and point out what was going on here on our planet when the light we see left Andromeda on its journey into our telescopes. We finish with a look at Andromeda’s collision course with our Milky Way. 

Next, we identify the local group of galaxies including: Triangulum with its great star birth H II region NGC 604; irregular galaxy NGC 6822 with its unique Hubble V H II region; the recently discovered galaxy IC 10; nearly edge on galaxy 3109; and Sextans A. 

We then cover 5 of the dwarf galaxies orbiting the Milky Way including Sagittarius Dwarf, Sculptor Dwarf and Fornax Dwarf along with the Large Magellanic Cloud and the Small Magellanic Cloud. Then we examine some of the amazing nebula within these two dwarf galaxies including: Supernova Remnant N 63A, SN 0509-67.5, the Tarantula Nebula, 30 Doradus, Hodge 301, the Double Bubble, LH 95, NGC 2074, NGC 602, NGC 346 and others. We conclude with a review of the galaxies we covered marked on a map of the Local Group.