Deep Sky Objects are astronomical objects that are beyond our solar system is a term used by amateur astronomers to describe mostly faint astronomical objects outside the solar system pre-historic times ancient greece ancient astronomy (c.100ad-c.1500ad) scientific revolution (c.1500ad-c.1800ad) modern astronomy History of the Discovery of Deep Sky Objects

Nebulae Galaxies Star Clusters Quasi-stellar Objects (Quasars)

Nebulae - interstellar cloud of dust, hydrogen gas and plasma - i n these regions the formations of gas, dust and other materials 'clump' together to form larger masses, which attract further matter, and eventually will become big enough to form stars - first stage of a star's cycle; often form star-forming regions NGC3603 Formation of Nebulae gravitational collapse of interstellar medium interstellar medium gas and dust that pervade interstellar space: the matter that exists between the stars within a galaxy result of supernova explosion supernova stellar explosions that are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy before fading from view over several weeks or months final stage of star’s life planetary nebula emission nebula consisting of a glowing shell of gas and plasma formed by certain types of stars when they die

Nebulae types of nebulae bright nebulae - general term for illuminated nebulae - diffused nebulae reflection nebulae - clouds of dust which are simply reflecting the light of a nearby star or stars emission nebulae - cloud of ionized gas (i.e. plasma) emitting light of various colors supernova remnant - structure resulting from the gigantic explosion of a star in a supernova - bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar material it sweeps up and shocks along the way. dark nebulae - interstellar cloud that obscures the light from the background stars - compressed nebulae planetary nebulae - nebula consisting of a glowing shell of gas and plasma formed by supernova explosion - relatively short-lived phenomenon witch head nebula pleaides nebula lagoon nebula heart nebula tycho supernova kepler nebula sting ray nebula hourglass nebula barnard’s e nebula snake nebula

Galaxies - massive, gravitationally bound system consisting of stars, an interstellar medium of gas and dust, and dark matter - range from dwarfs with as few as ten million stars up to giants with one trillion stars, all orbiting a common center of mass - categorized according to their apparent shape (usually referred to as their visual morphology) Formation of Galaxies top down theories protogalaxies form in a large-scale simultaneous collapse lasting about one hundred million years bottom up theories small structures such as globular clusters form first, and then a number of such bodies accrete to form a larger galaxy Sombrero galaxy Dynamics and Activities top down theories protogalaxies form in a large-scale simultaneous collapse lasting about one hundred million years galactic cannibalism process by which a large galaxy, through tidal gravitational interactions with a companion, merges with that companion, resulting in a larger, often irregular galaxy starburst process of an exceptionally high rate of star formation, compared to the usual star formation rate seen in most galaxies active galactic nucleus significant portion of the total energy output from the galaxy is emitted by a source other than the stars, dust and interstellar medium.

Galaxies spiral galaxies elliptical galaxies range in shape from nearly spherical to highly flattened ellipsoids composed of older stars, and minimal star formation activity lenticular galaxies - disc galaxies (like spiral galaxies) which have used up or lost most of their interstellar matter and therefore have very little ongoing star formation types of galaxies - consist of a rotating disk of stars and interstellar medium, along with a central bulge of generally older star sunflower galaxy andromeda galaxy ngc4649 / m60 ngc4552 / m89 cartwheel galaxy ngc1705

range in shape from nearly spherical to highly flattened ellipsoids

composed of older stars, and minimal star formation activity

Star Clusters - groups of stars which are gravitationally bound Christmas Tree Cluster Classification of Star Clusters - spherical collection of stars that orbits a galactic core as a satellite - very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers globular clusters - contain considerably more stars and are much older than the less dense galactic - generally composed of hundreds of thousands of low-metal, old stars - very loose star cluster, looser than both open clusters and globular clusters - gravitationally unbound and are still moving together through space 47 Tucanae Palomar 12 NGC3201 M9 NGC3201 open clusters - group of up to a few thousand stars that were formed from the same giant molecular cloud - loosely gravitationally bound to each other - have been found only in spiral and irregular galaxies, in which active star formation is occurring - they become disrupted by close encounters with other clusters a and clouds of gas as they orbit the galactic center, as well as losing cluster members through internal close encounters hodge301 wild duck cluster NGC2158 NGC604 super star clusters embedded clusters stellar associations - less dense globular clusters - Greater distance between stars intermediate clusters - very large region of star formation thought to be the precursor of a globular cluster - stellar clusters that are partially or fully incased in an interstellar dust or gas

Quasi-stellar radio sources (Quasars) - most distant and luminous objects in the universe - extremely powerful and distant active galactic nucleus - first identified as being high redshift sources of electromagnetic energy twinkle, twinkle, quasi-star, biggest puzzle from afar. how unlike the other ones, brighter than a trillion Suns. twinkle, twinkle, quasi-star, how I wonder what you are! - george gamow 3C 273, first quasar

Messier Catalogue New General Catalogue Herchel 400 Catalogue Caldwell Catalogue

Catalogue des Nébuleuses et des Amas d'Étoiles Catalogue of Nebulæ and Star Clusters (Messier Catalogue) - one of the first milestones in the history of discovery of deep sky objects - considered the first comprehensive and reliable list of astronomical objects - compilation of 110 astronomical objects observed by charles messier - popular viewing objects for amateur astronomers ( messier marathon ) note: the objects can only be found from the north celestial pole to 35º south of celestial equator notation: (m xxx)

Herchel 400 Catalogue - subset of william herchel’s original deep sky catalog of 2,500 objects ( gen. cat. ) - compilation of 400 out of 2500 objects observed by william herchel - all herchel 400 objects are in new general catalogue of deep sky objects - most visible using 150mm or larger telescopes note: herchel 400 objects are mostly visible in mid-northern latitudes notation: (h xxx) General Catalogue of Nebulae and Clusters - published by jon herchel in 1864 - compilation of 5000 deep sky objects (half of which came from the observations of william herchel) - main reference for herchel 400 catalogue and new general catalogue

Caldwell Catalogue - compilation of 109 astronomical objects observed by patrick caldwell-moore - compilation of objects that are already discovered by professional astronomers - serve as the complement of messier catalogue - criticized for having an egocentric approach and small compilation errors note: the objects can be seen in northern hemisphere and southern hemisphere notation: (C xxx) Messier Catalogue vs. Caldwell Catalogue (content) messier: list of interesting deep sky objects for observations caldwell: list of brightest deep sky objects (location of astronomical objects) messier: mostly northern hemisphere caldwell: both northern and southern hemisphere (order) messier: according to the date of discovery caldwell: according to declination

New General Catalogue - best known catalogue of deep sky objects in amateur astronomy - one of the largest comprehensive catalogues ( includes all types of d.s.o. ) - compilation of nearly 8,000 objects listed by j.l.e. dreyer in the 1880s note: the objects can be seen in northern and southern hemispheres however, the southern hemisphere is less catalogued notation: (ngc xxxx)