August & September 2017

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 Visible in August and September (during observatory hours)

 

Name / Designation

Apparent Magnitude
(lower = brighter)

Distance

(light-years)

Notes

Arcturus

-0.05

36.7

 

Vega

0.03

25

 

Capella

0.08

42

 

Altair

0.76

17

 

Spica

0.98

262

 

Markab

1.25

140

 

Deneb

1.25

3230

 

Regulus

1.36

77

means "Little King"

Polaris

1.97

431

 

Alpheratz or Sirrah

2.07

97

 

Denebola

2.14

36.2

 

Enif

2.38

670

 

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

Mercury will still be visible after sunset at the beginning of August, but will be passing between us and the sun before the end of the month.  It will reemerge in the morning sky in mid-September and be visble before sunrise for the rest of the month.

 

Venus remains visible in the morning sky before sunrise, coming up just slightly later each day.

 

Mars is still too close to the sun to see in August, but by early-mid September will emerge in the morning sky before sunrise.

 

Jupiter remains visible near the bright star Spica in the southwest after sunset, but sets earlier each night.

 

Saturn remains prominent throughout August and September near the foot of Ophiucus (between Scorpius and Sagittarius).

 

Jupiter Great Red Spot Transits during August and September (when the Flandrau dome is open)

NOTE: The GRS is visible on the disk of Jupiter for 50 minutes before and after meridian transit time.

Date

Meridian Transit Time

08/05/17

07:01 PM

08/12/17

07:50 PM

08/17/17

07:00 PM

08/19/17

08:39 PM

08/24/17

07:49 PM

 

Calendar of Night Sky Events

 

08/07/17

Full Moon.

08/12/17

Peak of Perseids meteor shower.

08/14/17

Last Quarter Moon.

08/21/17

New Moon and Total Solar Eclipse. Partially visible from Tucson.

08/26/17

Mercury at Inferior Conjunction. Between us and the Sun.

08/29/17

First Quarter Moon.

09/04/17

Neptune at opposition. Best time to look for our farthest planet.

09/06/17

Full Moon.

09/12/17

Mercury at greatest western elongation. Visible in the morning before sunrise.

09/12/17

Last Quarter Moon.

09/16/17

Appulse of Mercury and Mars. Separated by 0.06°.

09/19/17

New Moon.

09/22/17

Earth at Southward Equinox. Beginning of our Fall.

09/27/17

First Quarter 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 August and September (during observatory hours)

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 33

Triangulum Galaxy

5.7

67' x 42'

3,000,000

spiral galaxy

Messier 3

(in Canes Venatici)

6.2

18'

34,000

globular cluster

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 – What is special about this eclipse, and how can we (safely) see it?

The eclipse of August 21 is going to be the first total solar eclipse visible coast-to-coast across the US since 1918.  There of course have been other eclipses since then, but never have so many americans had the opportunity to see the same eclipse.  Even if you are not in the path of totality, you will get a partial view (Tucson will see the sun 67% eclipsed).  The next similar eclipse will be in 2045.

That being said, eclipses happen somewhere in the world several times per year.  Solar eclipses usually happen twice a year, but can sometimes happen up to five times if the timing is just right.  However, since the moon's shadow is so small, it is only visible from very specific locations.  Lunar eclipses happen just slightly more often than solar eclipses, but since the earth's shadow is much bigger, they are visible from nearly half of the earth.

Another factor to consider is that not every eclipse is total.  Just over one in four eclipses will be total, with the remainder being partial to some degree.  So seeing a total solar eclipse is a fairly rare experience unless you are willing to travel great distances.

To safely view a solar eclipse, you want to make sure you have special solar eclipse glasses.  Normal sunglasses are nowhere near as dark as necessary to be able to safely view the sun.  If you aren't able to obtain these special glasses, the only way to safely view the eclipse is indirectly, such as with a pinhole camera.  To make one of these, you just need a flat but sturdy piece of cardstock, such as from a cereal box.  Poke a small hole in the center two or three millimeters across.  Do not look through the hole, but instead hold it above a flat surface and an image of the sun should appear below the hole.  You can adjust the height to make the image bigger or smaller.

I and many of my friends will be travelling somewhere along the path of totality to see this eclipse.  If you are travelling as well, be safe and feel free to share your pictures if you wish!

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.