Spring 2012 Astronomy Course Mississippi Valley Night Sky Conservation The Sky Around Us Program developed by Mississippi Valley Conservation Authority Royal Astronomical Society of Canada Ottawa Astronomy Friends Instructors: Pat Browne Stephen Collie Rick Scholes Earth Centered Universe software for illustrations – courtesy David Lane

WHERE Locating Nebulae in Clusters Observing nebulousity around individual stars WHEN Are they Visible? WHAT Types of Nebulae Open Clusters and their Nebulae WHERE: > 500 light years (M42 is located at a distance of 1344 ± 20 light years and is the closest region of massive star formation to Earth.) This is much further out than… Nearest and Brightest stars 5-15 light years Consider: Lecture 1,II – Stars on the celestial sphere < 500 light years Famous Examples: Pleiades M42 trapezium (Astronomers suspect that shockwaves from a supernova explosion in Orion's head, nearly three million years ago, may have initiated this newfound birth). Nebulae in clusters and around our Galaxy

Introduction to Nebulae Observing Nebulae in ‘young’ star clusters Past the near objects, the planets, and beyond the double and variable stars is a special realm. Here are the star clusters, gas clouds and star nurseries. For most purposes it can be assumed that the stars in a given cluster formed simultaneously from the same parent cloud of gas and dust. When comparing star clusters, we often note the density of stars, their age and their chemical composition (as revealed by their spectra ). Young Star clusters also often exhibit nebulous trails of gas and dust which emanate from members that are still in the process of becoming stars! Also, those young stars often continue to radiate and reflect off of the dusty lanes that mark their birth into the cluster.

WHAT: Nebula in Open Clusters Observing (Winter) nebula in the Spring Western Sky Orion: M42, M78 Pleides: M45 Perseus: Double Star Cluster further NW (not shown) Open Clusters looking West (setting) ( Spring time Northern Hemisphere)

Open Clusters and Nebulous Regions in Constellation Auriga Auriga Auriga contains an interesting variety: many open clusters and nebulous regions simply because the Milky Way runs through it. 3 Open clusters in/out of pentagon of Constellation Auriga south of Capella. M37 the richest cluster containing over 500 stars spread across 20 arcminutes and is the brightest of the three with an apparent magnitude M stars with an angular width of 12 arcminutes.M38 100stars and is the dimmest of the three at magnitude+6.4. All three of these clusters, 4000 light-years away, can be seen with a small telescope. Courtesy - Dave Garner teaches astronomy at Conestoga

Observing nebulousity In Clusters in the western sky Observe: M42, the Great Orion Nebula M78 – Can you see the nebulousity in the double pair? M45 – Pleiades (the 7 sisters) – Can you see the nebulousity NGC 864, 869 : Double Cluster in Perseus (where’s the nebulousity?) M78 M42 M45 NGC 864,869