The ABCs of Stargazing How would you describe to a friend the size of a sky object, its distance from a particular star, its brightness, or its location on the celestial dome? The ABCs of stargazing allow you to do just that!

"A" is for angular size and distance Be sure to remember these handy references when discussing size or distance in the sky: • The moon spans 1/2º. It would take 360 "full moons" to reach from horizon to horizon! • The apparent width of the tip of your index finger on your extended arm is 2º. • The width of the bowl of the Big Dipper is 5º and the bowl's length is 10º. • Your clenched fist on your fully extended arm is 10º from side to side. • Your outstretched hand on your extended arm is 20º from the tip of the pinky to the tip of the thumb. Your fist Your index The Big Dipper 10º finder 2º 10º 5º Width of Moon's apparent size 3rd the Full relative to your Your hand Six of the seven stars Moon 1/2º clenched fist 20º of the Big Dipper are of the 2nd magnitude. "B" is for brightness Skywatchers use the "magnitude" scale to Mag. Object describe an object's brightness. Don't be -26 Sun (never look at the sun!) confused by the reverse nature of the scale: -12 Full moon The brighter the object, the smaller the -4 Venus magnitude. Objects with negative -2.5 Jupiter at its brightest magnitudes are very bright, indeed! -1.5 Sirius, the brightest star in the night 0Arcturus, Vega, Capella, Saturn Polaris, the North Star, always has an azimuth +1 Pollux, Regulus, Altair of 0º and has an altitude above the northern +2 Six stars of the Big Dipper, North Star horizon matching the latitude of the observer. +6 The faintest star seen by unaided eyes Zenith: North Star: Altitude = 90º Alt = Your Star: "C" is for coordinates Alt = 50º latitude Stargazers often use the simple, but Az = 0º Az = 150º descriptive altitude-azimuth (alt-az) system to locate objects in the sky. Horizon: Altitude = 0º E = 90º Azimuth coordinate: Altitude coordinate: North is 0º Horizon is 0º N = 0º East is 90º Zenith is 90º S = 180º South is 180º

West is 270º The Astronomical League, W = 270º www.astroleague.org/outreach Azimuth How do you find celestial objects? Finding celestial targets the modern way

Computerized "GoTo" telescopes ... the quick and easy method:

1 Level the telescope mount 5 Center on first guide star 2 Point the tube towards north 6 Center on second guide star 3 Indicate the date and time 7 Enter the target's designation 4 Indicate observing location 8 The scope automatically slews to it Finding celestial treasures the old fashioned way

1 Learn the stars Cassiopeia and constellations

There is no subsitute for sitting under the stars with a map and red flashlight. Use a star map that plots all stars visible to the unaided eye. Start by finding well-known star patterns such as the Big Dipper, or the constellation of Orion or Cassiopeia. Continue by identifying neighboring star patterns.

Target — NGC 7789 7789 2 Finderscope: little scope, big view Why a finderscope? β Cas Gives a wide field of view, about 5º, Must be aligned with the main telescope, Only the bright planets, brighter nebulae and star clusters are visible. Finderscope view, note the inverted image Simply... Point the finder at a suitable guide star, or Triangulate to the object by using nearby recognizable stars. The Big Dipper 3 Star Hopping: finding the faintest of objects... Eyepiece view Before hopping begins: of M108 β Must have a detailed star map. + Must know the field of view of the M108 eyepiece.

As an example, find galaxy M108: Begin hopping at a reference star, in this case Beta ( β ) Ursa Majoris in the Big Dipper. Match the stars on the map with those in the eyepiece. Hope among the stars in each subsequent field of view until the correct field is reached. Look closely to see the dim galaxy M108. Star hopping to M108 from Beta Ursa Majoris The Astronomical League www.astroleague.org/outreach Is that a planet or a star? Three tell tale visual characteristics a planet: 1 A planet shines with a steady light, unless it is very close to the horizon. It doesn’t “twinkle,” while a star does. Is that a2 Aplanet planet is always or located a star? near the ecliptic. Three tell tale visual characteristics3 A planet slowly a shiftsplanet: its position nightly with respect to the background stars. 1 A planet shines with a steady light, unless it is very close to the horizon. It doesn’t “twinkle,” while a star does. Sun appears in Leo next to its bright Is that a planet Sunor appears a instar? Virgo next to its star Regulus on August 23. 2 A planet is always located near the ecliptic. bright star Spica on October 17. Leo Three Is tellthat tale visual a planetcharacteristics or a planet: a star? Sun on 3 A planet slowly shiftsIs itsthat position a Isplanet nightly that with aor respectplanet a star?Sun to on theor Virgo a star? Mars on Cancer Oct. 17 Aug. 23 Celestial Sphere 1 Abackground planet shines stars. with a steady light, unless it isLibra very close to Oct. 17 Mars on Three tell tale visualThree tellcharacteristics taleThree visual tell characteristics tale visual a planet:characteristics of a planet: a planet: Ecliptic the horizon. It doesn’t “twinkle,” while a star does. Aug. 23 A planet shines with1. A planeta steady shines light, 1withA planet aunless steady shines light,withit isa steadyunlessverySun appearslight, itclose is unless very in to Leo itclose is verynext to closeto the its to bright 1 A planet is alwaysSun appears located in Virgonearthe horizon. next the to Itecliptic. itsdoesn’t “twinkle,”star Regulus while aon star August does. 23. the horizon.2 It doesn’thorizon.bright “twinkle,”It doesn’tstar Spica “twinkle,” onwhile October a while star17. a does.star does. 2 A planet is always locatedThe nearecliptic the ecliptic. denotes Leo Mars 2. AA planetplanet is slowlyalways shiftslocated its near position the ecliptic. nightly with respect to the 3 Sun on A planet slowly shiftsthe its position plane nightlyof the with solar respectSun on to the SUN Shifting position of a planet A planet is always located near3 theVirgo ecliptic. Mars on Cancer

background stars. Aug. 23 Celestial Sphere 2 3. Abackground planet slowly stars. shifts itsOct. position 17 nightly with respectsystem to projectedthe background onto stars. Oct. 17 against the starry backdrop. Libra Ecliptic Mars on the celestial sphere.Sun appears in Leo next to its bright Earth Aug. Earth 23 In this case, Mars moves in Sun appears in Virgo next to its 3 A planet slowly shifts its position nightly with Sunrespect appears toin Leo thestar next Regulus to onits August bright 23. Aug. 23 Oct. 17 front of the stars of Cancer, Sun appears in Virgo next to itsbright star Spica on October 17. Leo

Celestial Sphere star Regulus on August 23. background stars. Sun on then towards Leo. bright star Spica on October 17. Sun on Virgo Mars on Cancer

The ecliptic denotes Oct. 17 MarsLeo Aug. 23 Celestial Sphere Libra Ecliptic Oct. 17 Mars on the plane of the solar The SUN Ecliptic: TheSun onapparentShifting position path of ofa planetAug. the 23 sun across the celestial sphere Sun on Sun appears in Leo next to its brightMars on Cancer system projected onto Virgo against the starry backdrop. Sun appears in VirgoOct. 17 next to its Aug. 23 Celestial Sphere Libra star Regulus on August 23. Oct. 17 Mars on brightthe star celestial Spica onsphere. October 17.The ecliptic EarthEcliptic denotes Earth In Marsthis case, Mars moves in the plane of the solar SUN Shifting position ofAug. a planet 23 system Aug.projected 23 onto Oct. 17 Leo front ofagainst the thestars starry of backdrop. Cancer,

Celestial Sphere Mercury the celestial sphere. Earth Sun Earthon then towardsIn this case, Leo. MarsThe moves inInner Planets: Mercury and Venus Sun on Virgo Aug. 23 Oct. 17 Mars onfront of the Cancer stars of Cancer, Celestial Sphere The eclipticOct. 17 denotes • Either low above western Aug.horizonMars 23 in then towards Leo. Celestial Sphere Libra The Ecliptic: The apparent path of the sun across theOct. celestial 17 sphereWhenMars on Mercury or Venus move between the Earth and the plane of the solar The Ecliptic Ecliptic: The SUN apparent path of the sunShifting across position the celestial of a planetsphere the evening, or theAug. sun23 or when they orbit on the sun’s far side, they system projected onto • Low above the eastern horizon inagainst the the starry backdrop. the celestial sphere. In this case, Mars movesappear in near it in our day sky and can’t be seen. Mercury Mercury Earth Earth The Inner Planets: Mercury and Venus morning.Aug. 23The Oct. Inner 17 Planets: frontMercury of the starsand ofVenus Cancer, • Either low above western horizon in When Mercury or Venus move between the Earth and

Celestial Sphere The ecliptic denotes Mars • Either low above western horizonthe evening,in • A or challenge to spot. the sun or whenthen they towards orbit on the Leo. sun’s far side, they the plane of the solar • Low above the eastern SUN horizon When in the Mercury or VenusShifting move between position the of Eartha planet and the evening, or appear near it in our day sky and can’t be seen. Daily arc of the sun system The projected Ecliptic: onto The apparentmorning. path ofthe the sun orsun when across they orbit againstthe on celestial thethe sun’sstarry farsphere backdrop. side, they • Low above the eastern horizon •in A thechallenge to spot. appear near it in our day sky and can’t be seen. from sunrise to sunset. the celestial sphere. Venus In this Daily case, arc of Mars the sun moves in morning. Earth Earth Mercury Venus Aug. 23 Oct. 17 front fromof thesunrise stars to sunset. of Cancer, • A challenge to spot. • Dazzling white object. Celestial Sphere Mercury • Dazzling white object. After sunset: Either low above the western horizon in the evening,The Inner Planets: E Mercurythen towards andS Leo. Venus E S W • • Either• above Either the western above horizon the in western horizonDaily arc inof the sun W • Either low above western horizon in Planet is an or low above the eastern horizonthe evening, in the morning.When Mercury orWhen Venus Mercuryfrom moveor sunriseVenus liesbetween to to the sunset. theWhen Earth Mercury and or Venus evening lies to “star” theTheVenus evening, Ecliptic: or The apparent• or rising paththe above evening, theof eastern the horizon sun in acrossright of the sun,the it is a morningcelestial star the When sphereleft of the Mercury sun, it is an or Venus lies to the When Mercury or Venus lies to • A challenge to spot. the morning. the sun or whenand they can be orbit seen in theon eastern the sun’s farevening side, star they and can be found in • orBefore rising sunrise: above the easterntwilight before horizon sunrise. in theright western oftwilight the after sun, sunset. it is a morning star the left of the sun, it is an •• Low Dazzling above white the eastern object. horizon in• the Very easy to see. appear near it in our day sky and can’t be seen. and can be seen in the eastern evening star and can be found in morning. the morning.Planet is a E S W Venus• Either above the western horizon in morning “star” The Outer Planets: Mars, Jupiter, and Saturn Mars twilight before sunrise. the western twilight after sunset. Mercury••the EitherA challenge evening, above to the spot. western horizon • VeryThe easyWhen Inner Mercuryto see. Planets: or Venus lies toMercury the Whenand MercuryVenus or Venus lies to 4 The Inner Planets:• MercuryWhen it is close to and the Earth, Venus Mars is a very Daily arc of the sunthe left of the sun, it is an • Either low•in aboveor the rising evening, western above theorhorizon rising eastern inabove horizon the in 1 right Earth of the sun, it is a 3morning star bright red-orange object in the east after When Mercury Sun or Venus move between the Earth and Venusthe morning. and can be seen in the fromeastern sunrise tosunset, sunset.evening high in the star sky andnear canmidnight, be found and in in the evening,eastern or horizon in the morning. the west before sunrise. Mars Thethetwilight Outersun 2 orbefore when Planets: sunrise. they orbit Mars, on the Jupiter,sun’sthe far western side, and twilight they Saturn after sunset. •Dazzling Very easy white to see. object. W • Low above•• Dazzling the eastern white horizonobject. in the When the planet is opposite the sun, it rises near 1 appear near Eit in our day sky and Jupitercan’t be seen. •• VeryEither easy above to the see. western horizon in sunset and is visible all night. It is closest to the E 4 S W • When it is close to the Earth, Mars is a very morning. Earth and shines at its brightest. after sunset 1 Earth • When it is not positioned3 near the sun, Jupiter bright red-orange object in the east after the evening, When the planetWhen lies ahead Mercury of the Earth or in Venus their lies toMars the is Whenalways seenMercury as a brightor Venus pale yellow lies to object. • A challenge Theto spot. Outer Planets: Mars,2 Jupiter, and Saturn E Sun W Mars• or rising above the eastern horizon orbits,in it is seenright high in ofthe the east beforesun, itsunrise. is a Itmorning star the left of the sun, it is an sunset, high in the sky near midnight, and in is often said to be a “Morning Star” in the east. • When it is close to the Earth, Mars is a very When it is close to Earth, Mars 4 is a and can be seen in the Dailyeasternbefore arc sunriseof theSaturn sunevening star and can be found in the morning. 1 Earth When the planet moves3 on the far side of the sun, it appears in the day the west before sunrise. 3 twilight before sunrise.from sunrisebright red-orangeto sunset.• theWhen western it doesobject not twilight appear in the afterclose east sunset. after Venus sky near the sun and can’t be seen. 2 bright• Very red-orangeeasy to see. object in the Sun east to the sun, Saturn is seen as a When the Earth lies ahead of the planet in their sunset, high in the sky near midnight, and W in after sunset, high in the sky near 4 When the planet is opposite the sun, itbright rises creamy near starlike object. • Dazzling white object. orbits, it1 is seen high in the west after sunset and E the west W before sunrise. Jupiter 2 sets around sunsetmidnight. It andis often is said visible to be an all night. It is closest• It movesto the slowly with Erespect to midnight, and in the west before E Marsafter sunsetS W • Either above The the Outer western Planets: horizon inMars, Jupiter,“Evening Star” in theand west. Saturn the background stars. after sunsetAstronomical League Earth and shines at its W brightest. www.astroleague.org sunrise.When the planet is opposite the sun, it rises near Design by John Jardine Goss • When it is not positioned near the sun, Jupiter 1 • WhenJupiter it is closeWhen toMercury the Earth, or Venus Mars lies is toa very the evening, sunset and is visible all night. 4 It is closestWhen to the Mercury E or Venus lies to the 1 Earth rightWhen of the3 the sun, afterplanet it is sunset a liesmorning aheadbright star of the red-orange Earththe in left their object of the in sun, the iteast is an after is always seen as a bright pale yellow object. • or risingJupiter aboveEarth the and eastern shines at horizonits brightest. in 2 • When it is not positionedE near the sun, W Jupiter Sun and canorbits, be seenit is seenin the high eastern in thesunset, east highbefore eveningin sunrise.the sky star Itnear and midnight,can be found and in in the morning.WhenWhen it is the not planet positioned lies ahead nearof the theEarth in theiris often said to be a “Morningis alwaysStar” in seen the east. as a bright pale yellow object. 2 twilight beforeE sunrise. W the west beforethe westernsunrise. twilight afterbefore sunset. sunrise • Very easysun, to orbits,Jupiter see. it isis seen always high inseen the 2eastas a before very sunrise. It Saturn is often said to be a “Morning Star” in the east.When the planet moves W on the far side of the sun, it appears in the day brightWhen pale the planetyellow is oppositeobject. the sun, it rises near3 before sunrise Saturn 1 sky near the sun and can’tJupiter be seen. • When it does not appear close sunsetWhen andthe isplanet visible moves all night. on theIt is farclosest side toof the sun, itE appears in the day The Outer3 Planets: Mars, Jupiter, and Saturnafter sunset Mars• When it does not appear close to the sun, Saturn is seen as a SaturnEarthsky nearand shinesthe sun at andits brightest. can’t be seen. 4 When the Earth lies ahead• Whenof the itplanet is not in positioned their near the sun, Jupiter • Whento it the is closesun, Saturn to the is Earth, seen as Mars a is a very bright creamy starlike object. When2 WhenWhen it thedoes the planet Earth not lies lies 4appear ahead ahead of ofclose the the Earth planet to in theirin their orbits, it is seen high in theis always west after seen sunset as a bright and paleE yellow object. W 4 1 Earth 3 E W bright creamy starlike object. • It moves slowly with respect to the orbits,sun,orbits, Saturnit itis isseen seen is high highseen in inthe asthe east a west bright before after sunrise. sunset Itsetsand aroundE midnight.bright W It is often red-orange said to beobject an in the east after is often said to be a “Morning Star” in the east. after sunset sets around midnight. Sun It is often said to be an “Eveningbefore Star” sunrise in thesunset, west.Saturn• highIt moves in the slowly sky withnear respectmidnight, to and in the background stars. Astronomical League creamy starlike object. after sunset www.astroleague.org When“Evening the planet Star” inmoves the west. on the far side of the sun, it appears in the day the background stars. Astronomical League 3 2 the •west When before it does sunrise. not appear close www.astroleague.org Design by John Jardine Goss sky near the sun and can’t be seen. The Astronomical League, www.astroleague.org/outreach Design by John Jardine Goss W to the sun, Saturn is seen as a When the planetWhen isthe opposite Earth lies the ahead sun, of it the rises planet near in their 1 4 Jupiterbright creamy starlike object. sunset and isorbits, visible it isall seen night. high It inis the closest west toafter the sunset andE E W after sunset Earth and shinessets around at its brightest.midnight. It is often said to be an • It moves slowly with respect to after sunset • When it is not positioned near the sun, Jupiter “Evening Star” in the west. the background stars. Astronomical League When the planet lies ahead of the Earth in their is always seen as a bright pale yellow www.astroleague.org object. 2 E W Design by John Jardine Goss orbits, it is seen high in the east before sunrise. It is often said to be a “Morning Star” in the east. before sunrise Saturn 3 When the planet moves on the far side of the sun, it appears in the day sky near the sun and can’t be seen. • When it does not appear close to the sun, Saturn is seen as a When the Earth lies ahead of the planet in their 4 bright creamy starlike object. orbits, it is seen high in the west after sunset and E W sets around midnight. It is often said to be an • It moves slowly with respect to after sunset “Evening Star” in the west. the background stars. Astronomical League www.astroleague.org

Design by John Jardine Goss Our Moon Apparent Diameter: Langrenus: 82 miles in diameter, 30 arc minutes = 1800 arc seconds and about the same apparent size as Jupiter! True Diameter: 2160 miles Average distance from Earth: The Astronomical League 240,000 miles www.astroleague.org/ outreach

The Need for Telescopes Our solar system is very large and the planets are very far away. So far that, even though some of them are much larger than Earth, their angular sizes are qite small. Consequently, they always appear star-like to the unaided eye. A telescope is required to magnify their pinpoint appearances, making them visible as small disks for study. Magnifications of greater than 100 power are often needed.

Compare the relative apparent sizes of the moon and the bright planets with this circle which represents a typical low-power field of view. In many low-power eyepieces, the moon is about the same size as the field of view. Venus Mars Jupiter Mercury Saturn (greatest (closest) and its four large moons and its rings and (greatest brilliancy) Callisto, Ganymede, Io, and Europa elongation) its large moon Titan Io Europa Mars ( ) ( ) (farthest) Callisto Ganymede

Apparent Actual Distance at Diameter Diameter closest approach We all know how large the moon appears in our sky. (arc sec) (miles) (miles) While Venus, the planet that approaches closest to Mercury (closest) 10 3025 57 million Earth, has a true diameter of over three times that of Venus (closest) 60 7500 26 million our moon, it is always at least 108 times farther away. Earth --- 7900 --- Moon 1800 2160 220,000 As a result, its small angular size in the sky is Mars (closest) 25 4200 35 million comparable to the apparent sizes of the larger lunar Jupiter 47 88,000 390 million craters. The other planets appear even smaller. Saturn (planet) 19 75,000 794 million Saturn (rings) 40 155,000 794 million Selected objects visible on the First Quarter Moon Crater Aristillus Diameter: 34 miles Crater Aristoteles Diameter: 54 miles

Crater Eudoxus Diameter: 42 miles

Caucasus Mountains Sea of Serenity Apennine Mountains Sea of Sea of Crises Tranquility

X Apollo 11 Landing Site

Crater Langrenus Diameter: 82 miles

Crater Theophilus Diameter: 62 miles

Crater Piccolomini Diameter: 55 miles

Crater Furnerius Diameter: 78 miles

Crater Walther Diameter: 84 miles

Crater Maurolycus Diameter: 71 miles

The Astronomical League www.astroleague.org Selected objects visible on the Third Quarter Moon Crater Plato Diameter: 68 miles Mt. Pico Elevation: 7900 ft

Crater Aristillus Diameter: 34 miles

Apennine Mountains

Mt. Huygens Sea of Tallest lunar mountain, Rains Elevation: 15,400 ft

Crater Aristarchus Brigthest lunar feature, Diameter: 25 miles

Crater Eratosthenes Diameter: 36 miles

Crater Copernicus Diameter: 58 miles

Crater Grimaldi Diameter: 107 miles

Crater Ptolemaeus Diameter: 95 miles

Crater Bullialdus Diameter: 38miles

Crater Tycho Diameter: 51 miles Source of the major ray system

Crater Clavius Diameter: 140 miles

The Astronomical League www.astroleague.org All-Sky Map for January and February

January 10 p.m. February 8 p.m.

See Map Detail

Navigating the Night Sky Learn the sky by first finding those stars or constellations that you already know, such as the Big Dipper or Orion. This time of year, the Big Dipper lies low in the northeast and Orion is high in the southeast. Judge the relative positions of new stars from the ones you know.

Use the Big Dipper as a guide to find: Use Orion as a guide to find: The North Star Sirius, the brightest star in the night sky, Capella The Winter Triangle, Castor Aldebaran and the Hyades

To use this map: Face south and hold the map above your head. The stars on the map should match those in the sky. Selected Deep Sky Objects in the January through April early evening sky

To find star clusters M36, M37, and M38: 1. Locate the bright star Capella. It is nearly directly overhead. Locate reddish Aldebaran. 2. Locate the other four major stars of the pentagon of Auriga. The bottom one is really Beta Tauri. 3. Find Iota. It is 40% of the distance between Capella and Aldebaran. 4. M38 is half way along the line from Iota to Theta. Capella Distance: 4200 light-years. 5. M36 lies just north of the half way point between Theta Aurigae and Beta Tauri. Distance: 4000 light-years. 6. M37 lies just south of the half way point between 40% Theta Aurigae and Beta Tauri. Distance: 4500 Auriga light-years.

Theta M38 Aurigae Iota Castor Aurigae M36 M37 Pollux 50% Beta 60% M35 Gemini Tauri Hyades 50% Taurus Zeta Gamma Tauri Geminorum Aldebaran

To find star cluster M35: 1. Find the bright stars Pollux and Aldebaran. 2. Draw a line between them. 3. M35 is located 1/2 way between them. Distance: 2800 light-years. 4. The telescope will also show another open cluster, NGC 2158, as a small blur in the same field. Distance: 11,000 light-years.

THE ASTRONOMICAL LEAGUE www.astroleague.org

The Astronomical League www.astroleague.org Page 2 Selected Deep Sky Objects in the January and February (and November and December) early evening sky

Look nearly overhead for Pegasus, Andromeda, Perseus, and Cassiopeia

To find the Double Cluster: 1. Look half way between Alpha Cassiopeia To find Cluster M103: Persei and the "W" of Cassiopeia. Scan the area to the left of the bottom left star of 2. The Double Cluster appears as M103 a fuzzy blur to the unaided eye. Cassiopeia's "W." Distance: 7100 light-years Distance: 10,000 light-years

To find the ET Cluster: Alpha Persei, Double ET Mirfak Cluster 1. Scan the area to the right of Cluster the bottom left star of Cassiopeia's "W." 2. Some people think it resemble's ET (from the movie) raising a lit finger. Distance: 8000 light-years Beta Persei, Algol M34 Gamma To find Galaxy M31: Andromedae 1. Draw an arrow through the 40% 60% three rightmost stars of the "W" M31 of Cassiopeia. 2. Follow it until it hits M31. To find Cluster M34: Beta 3. This fuzzy galaxy will fill 1. Extend the handle of the dipper, Andromeda most of the field of view. known as the Great Big Dipper, Andromedae Distance: 2.5 million light-years formed by Pegasus, Andromeda, and Persusu. 2. M34 is 40% beteeen the last two stars of that dipper. 3. Use our lowest magnification. Distance: 1400 light-years Square of Pegasus Gamma Andromeda, Double Star: Use high magnification to reveal the two colorful components of Gamma Andromeda.

THE ASTRONOMICAL LEAGUE www.astroleague.org

The Astronomical League www.astroleague.org Page 3 All-Sky Map for March and April

March 11 p.m. EDT NORTH April 9 p.m. EDT

Cassiopeia

North Star

The Big Dipper The Milky Way The Double Cluster Arcturus Perseus

Capella Coma

EAST Cluster Zenith Auriga Leo The Pleiades + Castor

Pollux The WEST Hyades Aldebaran M44 Gemini The Ecliptic Regulus Betelgeuse Procyon Orion The Winter Triangle Rigel See Map Detail M42 Sirius

SOUTH Navigating the Night Sky Learn the sky by first finding those stars or constellations that you know, such as the Big Dipper or Orion. Judge the relative positions of the new stars from the ones you know. This time of year, the Big Dipper lies high in the northeast and Orion is high in the south or southwest.

Use the Big Dipper as a guide to View the large star cluster M44: find: It lies near the center of a triangle formed by The North Star Pollux, Regulus, and Procyon. The cluster Capella Use Orion as a guide to find: appears to the unaided eye as a smudge, but Castor Sirius, through a low-powered telescope, its many Leo The Winter Triangle, twinkling stellar lights can be easily seen. Arcturus Aldebaran and the Hyades Distance: 580 light-years.

To use this map: Face south and hold the map above your head. The stars on the map should match those in the sky.

The Astronomical League www.astroleague.org Page 4 Selected Deep Sky Objects in the March and April early evening sky

Betelgeuse

Procyon

3 Belt Stars Winter Orion Triangle 2/3 M42 M50 To find star cluster M50: Rigel 1. Locate Orion and the Winter Triangle stars of Betelgeuse, Sirius, and Procyon. To find nebula M42: 1. Find Orion's Belt. 2. M50 lies 1/3 between Sirius 1/3 and Procyon. 2. With unaided eye, look to Distance: 3200 light-years. the Belt's south for a fuzzy Sirius glow. That is M42, a nebula. Distance: 1300 light-years. M41

To find star cluster M41: 1. Find Orion and its Belt Stars. Relative field of view at 20 2. Find Sirius by extending a magnification (24 mm focal line formed by the Belt Stars to length on the zoom eyepiece). the southeast 3. M41 lies three field of views directly south. Distance: 2300 light-years.

THE ASTRONOMICAL LEAGUE www.astroleague.org

The Astronomical League www.astroleague.org Page 5

All-Sky Map for May and June NORTH

May 11:30 p.m. EDT June 10:30 p.m. EDT

Deneb Cassiopeia

Capella North Star

The Milky Way Vega Castor The Big Dipper Pollux EAST See Detailed Map Zenith + M44 WEST Coma Leo Cluster Procyon Arcturus The Spring Triangle Regulus

Ecliptic The

Spica

Antares

SOUTH Navigating the Night Sky Learn the sky by first finding those stars or constellations that you know, such as the Big Dipper. Judge the relative positions of the new stars from the ones you know. This time of year, the Big Dipper lies almost overhead.

Use the Big Dipper as a guide to View the large star cluster M44: find: Also called the Beehive, M44 lies near the The North Star, center of a triangle formed by Pollux, Deneb, Regulus, and Procyon. The cluster appears Arcturus then Spica, to the unaided eye as a smudge, but through Leo, a low-powered telescope, its many twinkling Castor stellar lights can be easily seen.

To use this map: Face south and hold the map above your head. The stars on the map should match those in the sky.

The Astronomical League www.astroleague.org Page 6 Selected Deep Sky Objects in the May and June early evening sky

Mizar, Double Star 1. Also in the field at low power is Alcor. 2. Use high power to "split" Mizar into two components. Big Dipper

Cor Caroli: Double Star M3, Globular Star Cluster 1. Moderately bright star located near the center of the arc of the Big 1. Located 40% between bright Dipper's handle. Arcturus and Cor Caroli. 2. Two colorful stars barely 2. The combined light of separated, use 60x magnification. 100,000 stars blends into a small, round fuzzy ball. Distance: 34,000 light-years. Coma This is a large open 60% Berenices cluster of approximately Cluster 50 stars. It is best seen with binoculars due to its large area. Distance: 260 light-years. 40% M3

Arcturus Galaxies M84, M86, and M87 Leo A very clear, dark night is needed to observe these three faint galaxies. 1. Located half way between Vindemiatrix and Denebola. 2. Each of these galaxies appears as a very dim and small fuzzy ball. They are a worthy challenge. Distance: 50 million light-years! Denebola

Vindemiatrix M84, M86, M87

The Astronomical League www.astroleague.org

All-Sky Map for July and August July 11:00 p.m. EDT NORTH August 10:00 p.m. EDT

Cassiopeia North Star

The Milky Way The Big Leo Dipper Deneb Coma Cluster See Map Detail Cygnus

EAST Vega Zenith The Summer +

Triangle WEST

Arcturus Altair

The Ecliptic Saturn Aquila See Map Detail Spica

Antares Sagittarius Scorpius

SOUTH

Navigating the Night Sky Learn the sky by first finding those stars or constellations that you know, such as the Big Dipper. Judge the relative positions of the new stars from the ones you know. This time of year, the Big Dipper lies high in the northwest.

The Milky Way stretches from Use the Big Dipper as a guide to find: the northeast, almost The North Star, overhead, then to the south. Deneb, and the other Summer Triangle stars of Vega and Altair, Scan with binoculars and Arcturus, telescope along its length for Spica many fascinating star clusters and small ill-defined nebulae.

To use this map: Face south and hold the map above your head. The stars on the map should match those in the sky.

The Astronomical League www.astroleague.org Page 8 Selected Deep Sky Objects in the July and August early evening sky

Lyra Lyra is a small constellation situated almost overhead in summer evenings. It is dominated by its bright star, Vega, third brightest star visible from the mid latitudes of the United States. Vega is also the brightest member of the "Summer Triangle."

Epsilon Lyrae A wide double star, easily split with low power. Under high magnifications, each star splits again, giving Epsilon its nickname: the Double-Double. Vega

Zeta Delta

Relative diameter of the field of view at low power.

Beta Lyrae Over a two week period, its brightness Gamma fluctuates between that M57 of Gamma and Zeta.

To find Planetary Nebula M57: Although it is called a "planetary nebula," it has nothing to do with the planets. 1. Find the parallelogram of Lyra. 2. M57 lies between the two lower stars of the parallelogram, Beta and Gamma Lyrae. 3. It appears very small and dim, and slightly oblong. Distance: 2000 light-years.

THE ASTRONOMICAL LEAGUE www.astroleague.org

The Astronomical League www.astroleague.org Page 9 Selected Deep Sky Objects in the July and August early evening sky

Enjoy the Constellation Scorpius Look for its signature fish hook shape standing above the southern horizon after darkness falls in July and August.

Globular Cluster M80: Beta 1. M80 is found half way between Antares and Beta Scorpii. Scorpii 2. It appears as a round, mottled ball containing the combined light of over 100,000 stars. 50% Distance: 33,000 light-years. M80

50% Open Clusters M6 and M7: M7 is visible to the unaided eye from a dark site. These two Antares clusters are best seen at low M4 power. Many stars fill the field. M6 Distance: 1600 light-years. Globular Cluster M4: M7 Distance: 800 light-years. 1. Place Antares on the eastern edge of the field of the lowest power eyepiece setting (24 mm). M6 2. M4 is found near the center of the field of view. It appears as a round, grainy ball containing the M7 combined light of over 100,000 stars. Distance: 7200 light-years. Shaula

Open Cluster NGC 6231: Point the telescope at Zeta and the NGC 6231 cluster's many stars sweep out to the northeast. Zeta Distance: 6000 light-years. Scorpii There is more than one cluster in the area. NGC 6231 has been called Relative diameter "The False Comet." of low power field of view THE ASTRONOMICAL LEAGUE www.astroleague.org

The Astronomical League www.astroleague.org Page 10

All-Sky Map for September and October September 10 p.m. EDT NORTH October 9 p.m. EDT

North Star The Big Dipper Cassiopeia

Andromeda

Deneb Arcturus EAST Vega Cygnus + Pegasus Zenith WEST The Summer Triangle

Altair Aquila The Milky Way

The Ecliptic Antares Fomalhaut Scorpius Sagittarius

SOUTH Navigating the Night Sky Learn the sky by first finding those stars or constellations that you know, such as the Big Dipper. Judge the relative positions of the new stars from the ones you know. This time of year, the Big Dipper lies high in the northwest. The Milky Way stretches from Use the Big Dipper as a guide to find: the northeast, overhead, then The North Star, to the south. Scan, with Deneb, and the other Summer Triangle stars of Vega and Altair, binoculars and telescope Arcturus, along its length for many Cassiopeia fascinating star clusters and small ill-defined nebulae.

To use this map: Face south and hold the map above your head. The stars on the map should match those in the sky.

The Astronomical League www.astroleague.org Page 11 Selected Deep Sky Objects in the September and October early evening sky

Enjoy the Constellation Sagittarius Look for its signature teapot shape pouring above the southern horizon after darkness falls in September and October. Scan the area for many distant star clusters and nebuale.

Relative diameter of the field of view using low power. M16 Both M16 and M17 are star forming nebulae. M16 is nicknamed "The Eagle Nebula," and M17 "The Omega Nebula." Globular Clusters M22 and M28: Both nebuale are 6000 light-years distant. Both of these round glows are composed of the combined light of over 100,000 stars. M17 M22 Distance: 11,000 light-years. M28 Distance: 18,000 light-years. Mu Sagittarii: Possibly the farthest star the unaided eye can The Iced Teaspoon see. Distance: 10,000 ligth-years.

Both M8 and M20 are star M20 forming nebulae with imbedded M22 star clusters. M8 is nicknamed M28 M8 "The Lagoon," M20 "The Trifid." M8 Distance: 4000 light-years. M20 Distance: 6000 light-years.

Both the star clusters M6 and M7 are large and bright. They nearly fill the field with many stars. M6 Distance: 1600 light-years. The Teapot M7 Distance: 800 light-years. M6

M7 Shaula

THE ASTRONOMICAL LEAGUE www.astroleague.org

The Astronomical League www.astroleague.org Page 12

All-Sky Map for November and December NORTH November 10 p.m. EST December 8 p.m. EST

The Big Dipper

North Star The Double Capella Cluster Auriga Cassiopeia Perseus Vega Cygnus Aldebaran Deneb The Pleiades AndromedaM31

EAST Overhead The The Hyades + Summer Triangle WEST The Milky Way The Great Square Aquila Altair Pegasus

The Ecliptic See Map Detail: January and February Map

Fomalhaut

SOUTH Navigating the Night Sky Learn the sky by first finding those stars or constellations that you know, such as the Big Dipper. Judge the relative positions of the new stars from the ones you know. This time of year, the Big Dipper hugs the northern horizon. The "W" of Cassiopeia lies high overhead.

Use the Big Dipper as a guide to find: The North Star, Deneb, and the other Summer Triangle stars of Vega and Altair, Capella

To use this map: Face south and hold the map above your head. The stars on the map should match those in the sky.

The Astronomical League www.astroleague.org Page 14