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

Spring Galaxy hunt M51 M64 M65.M66 Leo Triplet BlackEye Calaxy M64 WHERE Locating Galaxies by star-hopping Observing individual island Universes (poetic term) Observing interacting galaxies Observing clusters of galaxies (Virgo) WHEN Are they Visible? Spring time ! – due to our point of view on earth at this time of year WHAT Types of Galaxies (Face on, Edge on, Elliptical, Spiral, Barred Spiral, Irregular, Peculiar) WHERE: > 2 Million Light Years beyond the milky way Famous Examples: M64 – Blackeye Galaxy - Spiral M51 – Whirlpool Galaxy - Interacting Virgo Cluster of Galaxies – Our Local Group M65,M66 (and NGC 3628) – The Leo Triplet, M65, face on, M66 Edge On) M51 Whirlpool Galaxy M51 M64 Leo Triplet BlackEye Calaxy M64 M65.M66

Find a spiral galaxy M64 – The BlackEye Galaxy M51 Whirlpool Galaxy Locate the Right Angle of the constellation Coma Berenices You will see a swam of stars in there, Melotte 111 (Coma Star Cluster) Star Cluster in Coma Berenices– this is an open cluster! But we are after something much farther away outside of the Milky WAY! Locate the brightest star in Coma: Alpha Comae M64 is ~½ way between the diagonal of the Coma Constellation In the middle there is a bright star 35 Comae about 1 deg SW of M64 M64 is brighter than 10 billion suns (luminousity). However this depends on our distance estimate. Estimates of 10 to 40 Million Light Years are used for M64. Black band is dust which obscures part of the nucleus of the galaxy. Meridian BlackEye Calaxy M64 Alpha Comae 35 Comae

Galaxies … Where… Past the Milky Way… to other systems with billions of stars… As we dart away from our home galaxy at many times the speed of light to get to the next cluster of galaxies in the constellations of Virgo and Coma Berenices, we travel some 50 million light years As we reach the galaxies of Virgo and Coma Berenices, we realize that our local group is bound to this cluster –thousands of galaxies are sharing the same part of space, sharing the same destiny… (Deep Sky Objects, David Levy, p 188)

Find an interacting galaxy M51 – The Whilrpool Galaxy Locate the handle of the Big Dipper (star is called Alkaid) Locate the brightest star in the constellation Canes Venatici. This is Alpha CVn, (a famous double star called Cor Coroli) M51 is 1/3 the way to Cor Coroli from Alkaid (the handle of the big dipper)

M65,M66 and NGC 3628 The Leo Triplet System of Galaxies Spirals: Face and Edge-ON Find the three stars which make up the hind quarter of Leo.The lower right star is called Chort. Travel down until you see a dimmer star 73 Leonis. The galaxies are just southwest…