The University of Arizona

Skywatcher's Guides

Flandrau’s Observatory is operated entirely by volunteers. Please call ahead to see if the observatory is open (generally Thurs-Sat 7pm – 10pm). Our astronomer volunteers will help you experience the 16-inch telescope as well as answer your questions about the night sky.

Written by: Lucas Snyder (Flandrau Planetarium Operator)
Images contributed by: Tim Van DevenderAlistair Symon (Flandrau Telescope Operators), Nine Planets, and Students for the Exploration and Development of Space (SEDS)

Navigationphoto by Tim Van Devender

Stars and Constellations

In August we can still see part of the spring sky at the beginning of the night after sunset.  The bright star Spica in the constellation Virgo is low in the west-southwest.  A little higher in the west is even brighter Arcturus in the constellation Boötes. The easily recognizable Big Dipper (Ursa Major) is also visible in the northwest.  You can use two stars in the end of the bowl to find Polaris, the north star, which is the end of the handle of the Little Dipper (Ursa Minor). Next, high in the middle of the sky we see the summer constellations, with the three bright stars of the Summer Triangle being the most prominent.  Vega is the highest and brightest of the three, with Deneb below towards the east and Altair to the southeast.  Then Scorpius with the bright star Antares is visible to the south-southwest, and the "teapot" of Sagittarius is nearby towards the south. The summer Milky Way is prominent this time of year stretching all the way across the sky from south-southwest to north-northeast.  Next, the fall sky is beginning to rise in the east at the beginning of the night.  The "great square" of Pegasus is low towards the east and Andromeda is adjacent to the northeast. Cassiopeia is a little higher in the northeast, and appears as a "W" this time of year.

 

In September, Boötes is now low in the sky towards the west-northwest.  The Big Dipper is also very low in the northwest.  Polaris and the Little Dipper are of course still in the North.  Now Scorpius is low in the southwest, and we can see the Sagittarius "teapot" in the south-southwest.  The Summer Triangle is still up in the middle of the sky, and the summer Milky Way is still a prominent streak across the sky.  Next, Pegasus and Andromeda are higher in the east, and you might be able to find the Andromeda Galaxy. Cassiopeia is higher in the northeast and is starting to rotate to a "3" orientation. Finally, below that you may see Perseus along the horizon at the beginning of the night.

 

 Interesting Stars to Observe

Name / Designation

Apparent Magnitude
(lower = brighter)

Distance

(light-years)

Notes

Sirius

-1.44

8.6

 

Arcturus

-0.05

36.7

 

Vega

0.03

25

 

Capella

0.08

42

 

Rigel

0.18

770

 

Procyon

0.4

11

 

Betelgeuse

0.45

427

 

Altair

0.76

17

 

Aldeberan

0.87

65

 

Spica

0.98

262

 

Pollux

1.16

38

 

Markab

1.25

140

 

Deneb

1.25

3230

 

Castor

1.58

52

 

Polaris

1.97

431

 

Alpheratz or Sirrah

2.07

97

 

Mirach

2.07

199

 

Algol

2.09

93

variable star

Denebola

2.14

36.2

 

Enif

2.38

670

 

Almak

2.1 / 5.0 & 6.3

355

 triple star system w/ 64 yr orbit

Albireo

3.2 / 5.8 & 5.1

390 / 380

 possibly a triple star system

Eta Cassiopeiae

3.5 / 7.4

19

480 yr orbit

 

Solar System

Venus is visible in the morning sky before sunrise.

 

Jupiter is now emerging from behind the sun and will be visible in the morning before sunrise in the constellation of Cancer.

 

Mars is still fairly high in the sky at the beginning of the night in the constellation Libra, and is visible for a few hours after sunset. 

 

Saturn is also in the constellation Libra, fairly high at the beginning of the night, and is up for a few hours after sunset.

 

Mercury will be passing behind the Sun in early August, but will be visible in the evening sky in September.

 

 

Calendar of Night Sky Events during June and July

08/02/14

Conjunction of Mercury and Jupiter.

08/03/14

First Quarter Moon.

08/08/14

Mercury at superior conjunction. Now hidden behind the sun.

08/10/14

Full Moon "Supermoon" - the largest full moon of the year.

08/12/14

Peak of Perseids meteor shower. One of the best showers of the year.

08/17/14

Last Quarter Moon.

08/17/14

Conjunction of Venus and Jupiter.

08/25/14

New Moon.

08/25/14

Conjunction of Mars and Saturn.

08/29/14

Neptune at opposition. Best time of year to see this planet through a telescope.

09/02/14

First Quarter Moon.

09/08/14

Full Moon.

09/15/14

Last Quarter Moon.

09/17/14

Comet Oukaïmeden at brightest. Unfortunately only up during daylight.

09/21/14

Mercury at greatest eastern elongation. Visible in the evening after sunset.

09/22/14

Earth southward equinox. The beginning of our autumn.

09/23/14

New Moon.

 

Deep Sky

There are many deep sky objects we can see since the summer Milky Way is high in the sky.  There are many open star clusters that can be seen with only binoculars scanning this part of the sky.  For example we have the Butterfly Cluster (M6) and Ptolemy's Cluster (M7) near the tail of Scorpius.  Further north there is the Wild Duck Cluster (M11) in the faint constellation of Scutum between Sagittarius and Aquila.  There is also the asterism of the Coathanger between Aquila and Cygnus in the fainter constellation of Vulpecula.  Next, heading towards the west we can see the Coma Star Cluster in the constellation of Coma Berenices, which is even visible naked-eye.  The Pleiades (M45) will be visible later in the night, after midnight.

 

There are a several globular clusters we can see as well, as the center of our galaxy is the highest it gets for the year.  Near the bright star Antares in Scorpius lies the globular cluster M4.  In Sagittarius we also have the Teapot Cluster (M22).  Of course we have the famous Hercules globular (M13) high in the east.  Also, M15 is visible in the east near the head of Pegasus.

 

For nebulae, we have several in the plane of the galaxy, one of which is the Swan Nebula (M17) in Sagittarius, also known as the Omega Nebula.  There is also the Lagoon Nebula (M8) nearby and the North America Nebula (C20) further north in Cygnus.  For planetary nebulae we have the Ring Nebula (M57) in Lyra, the Dumbell Nebula (M27) in Vulpecula, and the Blue Snowball (C22) in Andromeda.

 

And now the galaxies:  Although the Big Dipper is getting lower in the sky, you may still be able to find some of the galaxies in this part of the sky.  We have the Whirlpool Galaxy (M51) and the Pinwheel Galaxy (M101) near the handle, and the Cigar Galaxy (M82) and Bode's Galaxy (M81) near the bowl.  The spectacular Andromeda Galaxy (M31) is now coming up in the northeast, along with the nearby Triangulum Galaxy (M33).

 

 Interesting Deep Sky Objects to Observe during June and July

Designation

Name

Apparent Magnitude

Apparent Size

Distance

(light-years)

Type

Messier 45

Pleiades

1.6

110'

440

open cluster

Messier 31

Andromeda Galaxy

3.4

3° x 1°

2,900,000

spiral galaxy

Messier 44

Beehive Cluster

3.7

95'

577

open cluster

Messier 33

Triangulum Galaxy

5.7

67' x 42'

3,000,000

spiral galaxy

NGC 7009

Saturn Nebula

8

36"

2,400

planetary nebula

Messier 81

Bode's Galaxy

8.5

21'

1,200,000

spiral galaxy

Messier 82

Cigar Galaxy

9.5

14'

1,200,000

galaxy

 

Frequently Asked Questions – Why is Pluto not a planet anymore?

Just about everyone over the age of 10 remembers Pluto as the ninth planet in our solar system.  However, in 2006, the International Astronomical Union "kicked it out."  The IAU wasn't just being mean, so to speak; there actually was a logical reason for that decision.

 

Pluto was discovered in 1930 by sheer coincidence.  Neptune had been found by looking for irregularities in Uranus's orbit, so by doing the same for Neptune, astronomers thought they could detect another object pulling on it.  They predicted a position for this theoretical ninth planet, and Pluto just happened to be there.  Preliminary data indicated that this object could be as big as the Earth, but subsequent measurements indicated it was much smaller.  This new object was not nearly big enough to perturb Neptune's orbit, and when they went back and looked at Neptune again, they did not find the irregularities they thought they saw earlier.  However, at the time Pluto was the only known thing past Neptune, so they decided to keep it as a planet.

 

Over the decades, other things were found past Neptune that were in similar orbits to Pluto's.  None of them were as big as Pluto, so it retained its title as the ninth planet.  But in 2005, an object was found that called Pluto's title into question.  This object is named Eris.  At first Eris was thought to be just slightly larger than Pluto. (It is now thought to be just slightly smaller.)  So if Pluto is a planet, then Eris should be too.  But what about the other objects that are almost as big as Pluto?  Where would we draw the line?  Any line we choose would pretty much be arbitrary.  This is what prompted the IAU to come up with a formal definition of what is a planet and what is not.

 

The name planet means "wanderer," refering to the movement of the planets in the sky.  The Sun and the moon were considered planets in ancient times, but the Earth was not.  It was Copernicus's idea to rearrange things to the more familiar system we used for hundreds of years.  In 2006, the IAU came up with three criteria for something to be considered a planet: 1) the object has to orbit the sun, 2) the object has to be big enough to be round by its own gravity, and 3) it has to have "cleared its neighborhood."  This third criterion is the one that Pluto didn't meet.  So many other things were found sharing Pluto's orbit that it is now called the Kuiper Belt.  It is similar to the asteroid belt, but more icy.  In fact, some of the asteroids were called planets too when they were first discovered (so even Jupiter was considered the ninth planet at one point), but they basically got demoted for the same reason.

 

That's not the end of the story, however.  Pluto is now called a dwarf planet.  Basically, anything that meets the first two criteria and not the third gets this "consolation prize."  Currently, we have five official dwarf planets: Ceres, Pluto, Haumea, Makemake, and Eris.  There could potentially be hundreds more out there waiting to be discovered.

 

If you have any questions you'd like me to answer in the next issue of SWG, please let me know.  I'm also happy to take suggestions or comments, and also pictures if you'd like to send them.  Happy viewing!

 

Table of Images (Click on an image to expand)

Sketches and Images - Image Credit (Tim Van Devender)

Mars

Mars

Saturn

Saturn

Jupiter

Jupiter

The Moon

The Moon

Jupiter and Io Moon Shadow

Jupiter and Io Moon Shadow

Messier 45 (Pleiades)

M45

NGC 884 and NGC 869 - Perseus Double Cluster

NGC 884 and NGC 869 - Perseus Double Cluster

NGC 2024 - The Horsehead and Flame Nebulae

NGC 2024 - The Horsehead and Flame Nebulae

NGC 2237 - The Rosette Nebula

NGC 2237 - The Rosette Nebula

NGC 2264

NGC 2264

Images from Alistair Symon
Messier 27 (Dumbbell Nebula)

M27

Mssier 31 (Andromeda Galaxy)

M31

Messier 33 (Triangulum Galaxy)

M33

Messier 45 (Pleiades)

M45

Messier 57 (Ring Nebula)

M57

Images from Nine Planets
Jupiter

Jupiter

The Moon

The Moon

Images from SEDS
Messier 13 (Hercules Globular Cluster)

M13

Messier 15

M15

Messier 27 (Dumbbell Nebula)

M27

Messier 31 (Andromeda Galaxy)

M31

Messier 33 (Triangulum Galaxy)

M33

Messier 44 (Beehive Cluster)

M44

Messier 45 (Pleiades)

M45

Messier 57 (Ring Nebula)

M57

NGC 7009 (The Saturn Nebula)

NGC 7009

NGC 7293 (The Helix Nebula)

NGC 7293

 

Bibliography

Cornelius, Geoffrey. The Starlore Handbook: an Essential Guide to the Night Sky. San Francisco, CA: Chronicle, 1997. Print.

Ottewell, Guy. Astronomical Calendar 2012. Raynham, Mass: Universal Workshop, 2011. Print.

Ottewell, Guy. Astronomical Calendar 2013. Raynham, Mass: Universal Workshop, 2012. Print.

Ottewell, Guy. The Astronomical Companion. 2nd ed. Raynham, Mass: Universal Workshop, 2010. Print.

 

Astronomy Magazine. February 2013. Volume 41, No 2.

Astronomy Magazine. February 2013. Volume 41, No 3.

Sky & Telescope. February 2013. Volume 125, No 2.

Sky & Telescope. March 2013. Volume 125, No 3.