December 2015 & January 2016

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 December, the summer constellations are still visible for the first few hours of the night towards the west.  The Summer Triangle is still fairly high, with Vega heading to the west-northwest, Deneb closest to the zenith, and Altair in the west-southwest.  The center of the Milky Way is now below the horizon, but there is still a good portion of our galaxy we can see streaking high across the sky. The fall sky is now very prominent, getting high in the eastern sky.  The "W" of Cassiopeia is very high in the north-northeast. In the absence of the Big Dipper (part of our spring sky) Cassiopeia can be used to locate the north star: The top (open side) of the "W" faces to the north, so in that direction look for a star about the same brightness as the main stars in Casssiopeia, and that will most likely be Polaris.  Next, the Great Square of Pegasus is nearly in the middle of the sky.  Andromeda is nearby in the northeast, with Perseus just below.  There is also a fairly bright star called Fomalhaut in the south, though its constellation Piscis Austrinus is not easy to distinguish.  Finally, the winter sky is beginning to come up along the eastern horizon.  Taurus the bull is now up in the east with the bright star Aldebaran and the Pleiades (aka the seven sisters or Subaru) star cluster.  Auriga the charioteer is also up in the northeast, with the bright star Capella.

 

In January, the summer constellations are now very low in the west.  Deneb is the highest point of the Summer Triangle in the northwest, with Vega below near the horizon, and Altair more towards the west.  The Milky Way continues to streak across the sky, though the summer portion is now giving way to the winter portion.  The fall constellations are now right in the middle of the sky.  More of the winter constellations are now up, most notably Orion the hunter in the east below Taurus.  Gemini the twins are also up in the east-northeast just below Auriga.

 

 Interesting Stars Visible in December and January (during observatory hours)

 

Name / Designation

Apparent Magnitude
(lower = brighter)

Distance

(light-years)

Notes

Sirius

-1.44

8.6

 

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

 

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

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

Mercury emerges from the glare of the sun in mid-December and will be visible in the evening after sunset. By early January it will be lost again as it makes its way around between us and the sun, but will begin to emerge again in the morning sky by the end of January.

 

Venus is visible in the morning sky before sunrise, descending through Libra in December and Scorpius in January.

 

Mars is rising a little earlier each morning, passing through the constellation of Virgo and into Libra.

 

Jupiter is still hovering near Leo the Lion, which rises more and more each night, eventually coming up before midnight by mid-January.

 

Saturn is emerging from behind the sun in the morning sky in mid-December, getting fairly high by the end of January. It is in the constellation of Scorpius, near the bright star Antares.

 

Calendar of Night Sky Events

 

12/03/15

Last Quarter Moon.

12/07/15

Moon occults Venus. Happens during daylight, but could be seen with a telescope.

12/11/15

New Moon.

12/14/15

Peak of Geminids meteor shower.

12/18/15

First Quarter Moon.

12/21/15

Earth at Southern Solstice. Beginning of our Winter.

12/25/15

Full Moon.

12/28/15

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

01/01/16

Last Quarter Moon.

01/02/16

Earth at perihelion. Our closest approach to the sun for the year.

01/08/16

Venus and Saturn in conjunction. Separated by only 5 arcminutes (0.09°).

01/09/16

New Moon.

01/11/16

Comet Catalina at brightest. Visible several hours before sunrise.

01/14/16

Mercury at inferior conjunction. Between us and the sun.

01/16/16

First Quarter Moon.

01/23/16

Full Moon.

01/31/16

Last Quarter Moon.

 

Deep Sky

The summer Milky Way is now partially below the horizon at the beginning of the night, but the winter Milky Way is getting more and more prominent.  There are many open star clusters that can be seen with only binoculars scanning this part of the sky.  For example we have the asterism of the Coathanger between Aquila and Cygnus in the fainter constellation of Vulpecula.  The Pleiades (M45) is visible naked-eye in the east just above the face of Taurus which itself is another cluster called the Hyades.  We also have the Double Cluster in Perseus high in the north-northeast.  Finally, the constellation of Auriga in the northeast contains M36, M37, and M38 in close proximity.

 

There aren't as many globular clusters we can see this time of year, but there are still a few.  M15 is visible near the head of Pegasus in the west-southwest.  The next brightest one is M2 in Aquarius to the southwest.

 

For nebulae, we have several in the plane of the galaxy, one of which is the North America Nebula (C20) to the west-northwest in Cygnus.  The spectacular Orion Nebula (M42) is now just rising at the beginning of the night in the east. 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:  Our neighbor the Andromeda Galaxy (M31) is now very high in the middle of the sky and is visible on dark nights with the naked eye.  Also nearby is the Triangulum Galaxy (M33), visible with binoculars.

 

 Interesting Deep Sky Objects to Observe during December and January (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 44

Beehive Cluster

3.7

95'

577

open cluster

Messier 42

Orion Nebula

4

85' x 60'

1400-1600

diffuse nebula

Messier 33

Triangulum Galaxy

5.7

67' x 42'

3,000,000

spiral galaxy

NGC 7293

Helix Nebula

7.3

16'

450

planetary nebula

Messier 27

Dumbbell Nebula

7.4

8' × 6'

1,250

planetary nebula

NGC 7009

Saturn Nebula

8

36"

2,400

planetary nebula

Messier 81

Bode's Galaxy

8.5

21'

1,200,000

spiral galaxy

Messier 57

Ring Nebula

8.8

1'

2,300

planetary nebula

Messier 82

Cigar Galaxy

9.5

14'

1,200,000

galaxy

 

Frequently Asked Questions – Why do we have constellations?

This is a fun one.  We all know about how stars can be connected dot-to-dot to make pictures in the sky.   You may even know some of the stories that go along with the constellations.  But where did they come from?  Why do we even have constellations in the first place?  This one is not so much a science question as it is about history and culture.

Long ago, people didn't have televisions (I know, hard to imagine) and needed something to entertain themselves at night.  The stars are more or less fixed in the sky, night after night, year after year, and since they were an agricultural society, they needed to be familar with these patterns.  So why not make up stories to help them remember?

Some of the ancient civilizations that are represented in our modern constellations are the Greek, Roman, Babylonian, Egyptian, Hebrew, and Arabic cultures.  But these aren't the only civilizations to come up with pictures and stories.  Hindu, Chinese, African, Native American, and many other cultures each have their own ways of grouping the stars together. Ultimately, the constellations are arbitrary -- There's no physical connection between most stars in the sky -- so no particular grouping could be considered "right" or "wrong".

But now let's get back to modern times.  Our 88 modern constellations were designated in 1922 by the International Astronomical Union.  Their goal was to map every part of the sky to a particular constellation.  in 1930, official boundaries were constructed between each of these constellations using perfect north-south and east-west lines.  A problem, though, is that the Earth's axis wobbles, and over time these lines have slanted so that they are no longer perfectly north-south and east-west.  Another thing is that stars move (slowly) relative to each other, so they could end up crossing a boundary from one constellation into another.  But unless you are looking thousands of years into the past or future, it won't make that much of a difference.

So now the current definition of a constellation is no longer the dot-to-dot connections between the stars, but rather the area within the defined boundaries.  When astronomers use the constellations today, they are merely saying that they are looking at something within that area, not necessarily one of the bright stars that make up the picture we are used to.  The dot-to-dot connections are now referred to as asterisms.  Asterisms could be entirely within the boundaries of a particular constellation, or they could join together stars from different constellations.  Some well known asterisms are the Big Dipper, the Summer Triangle, the Teapot, and the Northern Cross.  These are often more recognizable than the constellations themselves.  But like the pictures the ancient stargazers saw in the heavens, there is no right or wrong way to do it, so you can come up with your own if you like!

 

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.