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Kiss the Sky Tonight -- Month of December 2020

Posted by Guy Pirro   12/07/2020 12:02AM

Kiss the Sky Tonight -- Month of December 2020

A view showing how the Jupiter-Saturn conjunction will appear in a telescope pointed toward the western horizon at 7:00 PM EST, December 21, 2020. Jupiter and Saturn have been traveling across the sky together all year, but this month, get ready for them to really put on a show. Over the first three weeks of December, watch each evening as the two planets get closer in the sky than they've appeared in two decades. Look for them low in the southwest in the hour after sunset. And on December 21st, the two giant planets will appear just a tenth of a degree apart – that's about the thickness of a dime held at arm's length. This means the two planets and their moons will be visible in the same field of view through binoculars or a small telescope. In fact, Saturn will appear as close to Jupiter as some of Jupiter's moons. [Video Credits: NASA, JPL – Caltech, and the Office of Public Outreach – STScI, and WQAD-TV 8 ABC/MyNetworkTV affiliate] [Image Credit: Adapted by Patrick Hartigan from the open-source planetarium software Stellarium, used under GPL-2.0, and provided under CC BY 4.0 courtesy of Patrick Hartigan]



Kiss the Sky Tonight -- Month of December 2020

Welcome to the night sky report for December 2020 -- Your guide to the constellations, deep sky objects, planets, and celestial events that are observable during the month. Step outside on a cold December night when the stars shine bright to find the Big Dipper, Cassiopeia, and Cepheus. They will help you locate a binary star system, a fan-shaped open star cluster, and a variable star. Also this month, catch the Geminids meteor shower. Then see Jupiter and Saturn come together in a conjunction to form a "double planet." Just after sunset on the evening of December 21st, Jupiter and Saturn will appear closer together in Earth’s night sky than they have since the year 1226 -- That’s 800 years ago during the Middle Ages. Is this like the Star of Bethlehem? No, not really -- I realize it is just two planets coming together in the sky (not a star), it’s pointing west instead of east, and it is a few days early for Christmas, but I couldn’t resist making the connection, so work with me here. (Interesting side fact, some have speculated that the true Star of Bethlehem could have been the conjunction of Jupiter and Venus near the bright star Regulus that occurred in the year 2 BC). The night sky is truly a celestial showcase. Get outside and explore its wonders from your own backyard.

The long, frosty nights of December make for good sky gazing when the stars shine clear and bright. Face north to find the Big Dipper scraping the northern horizon.

The constellation of Cassiopeia the queen swings high on the other side of Polaris, the North Star. The constellation forms a clear “W” or “M” shape in the sky. Snuggled in the W pattern is Eta Cassiopeiae, a binary with a pale yellow Sun-sized star and a less massive orange companion.

Also tucked within the W pattern is the open star cluster M103. Binoculars or a small telescope show a fan-shaped group of about 170 stars, with a red giant star near the center.





To the east of Cassiopeia lies the fainter constellation of Cepheus, the king. His dim shape looks like the outline of a house. Along the base of the house lies Mu Cephei, a red giant also known as the Garnet Star for its deep red color. It’s also a variable star, changing in brightness over a period of hundreds to thousands of days.

To one side of the house’s base sits NGC 6946, a ragged spiral galaxy that appears as a ghostly patch of light in modest telescopes. NGC 6946 is known as the Fireworks Galaxy because of the frequency of supernovas occurring within it -- 10 within the past century. By comparison, the larger Milky Way averages just two per century. When viewed in the X-ray part of the spectrum, it reveals a galaxy filled with remnants of supernovas, whose energy contributes to heating the surrounding gas.

To the west of Cassiopeia we find the sprawling pattern of Perseus, the Greek hero and slayer of Medusa, whose head he carries. Among Perseus stars lies the open star cluster M34. Small telescopes or binoculars show a concentrated scatter of about 100 stars.

Face north to locate the Big Dipper and find galaxy M82. In binoculars and small telescopes, the galaxy appears as a thin rod of light. M82, seen edge-on, experienced a tremendous burst of star formation after an encounter with another galaxy. Multi-wavelength images show the effects of this starburst as it blows out dust and hot gas from its central regions.

Face east to find Orion the hunter with his shining belt rising over the early winter landscape. The glittering stars of winter rise with Orion and promise many fine stargazing nights to come.




December also brings one of the most reliable annual meteor showers, and one of the best in 2020 -- the Geminids. This shower is active from December 4th through the 17th, as Earth plows through the trail of dusty debris left behind in the orbit of asteroid 3200 Phaethon, which might actually be a burnt-out comet.

The Geminids produce a good number of meteors most years, but they're made even better this year as the shower's peak coincides with a nearly new moon, thus making for darker skies with no moonlight to interfere with the fainter meteors. The Geminids peak overnight on December 13th into the morning of the 14th, with some meteor activity visible in the days before and after. Viewing is good all night for the Northern Hemisphere, with activity peaking around 2:00 AM local time, and after midnight for viewers in the Southern Hemisphere.

For the best viewing, find a safe location away from bright city lights and look up. Meteors can appear in any part of the sky, though they'll appear to primarily radiate from near the constellation Gemini.



The Star of Bethlemem? (No, not really)

Jupiter and Saturn have been approaching one another in the night sky since the summer. From Dec. 16 to 25, the two will be separated by less than the diameter of a full moon.

Just after sunset on the evening of Dec. 21, Jupiter and Saturn will appear closer together in Earth’s night sky than they have been since the Middle Ages, offering people the world over a celestial treat to ring in the winter solstice in the northern hemisphere and the summer solstice in the southern hemisphere.

“Alignments between these two planets are rather rare, occurring once every 20 years or so, but this conjunction is exceptionally rare because of how close the planets will appear to one another,” says Rice University astronomer Patrick Hartigan. “You’d have to go all the way back to just before dawn on March 4, 1226, to see a closer alignment between these objects visible in the night sky.”

“On the evening of closest approach on Dec. 21 they will look like a double planet, separated by only 1/5th the diameter of the full moon,” said Hartigan, a professor of physics and astronomy. “For most telescope viewers, each planet and several of their largest moons will be visible in the same field of view that evening.

This event is called a "great conjunction." These occur every 20 years or so as the orbits of Earth, Jupiter, and Saturn periodically align making these two outer planets appear close together in our nighttime sky. Even so, this is the "greatest" great conjunction between Jupiter and Saturn for the next 60 years, with the two planets not appearing this close in the sky until 2080.

Though the best viewing conditions will be near the equator, the event will be observable anywhere on Earth, weather-permitting. Hartigan said the planetary duo will appear low in the western sky for about an hour after sunset each evening.

“The further north a viewer is, the less time they’ll have to catch a glimpse of the conjunction before the planets sink below the horizon,” he said. Fortunately, the planets will be bright enough to be viewed in twilight, which may be the best time for many viewers to observe the conjunction.

“By the time skies are fully dark in Houston, for example, the conjunction will be just 9 degrees above the horizon,” Hartigan said. “Viewing that would be manageable if the weather cooperates and you have an unobstructed view to the southwest.”

But an hour after sunset, people looking skyward in New York or London will find the planets even closer to the horizon, about 7.5 degrees and 5.3 degrees respectively. Viewers there, and in similar latitudes, would do well to catch a glimpse of the rare astronomical sight as soon after sunset as possible, he said.

Those who prefer to wait and see Jupiter and Saturn this close together and higher in the night sky will need to stick around until March 15, 2080, Hartigan said. After that, the pair won’t make such an appearance until sometime after the year 2400.

Dec. 21st is also the date of the December solstice, which is the winter solstice in the Northern Hemisphere and the summer solstice in the Southern Hemisphere. On the December solstice, the Sun reaches its southernmost position in the sky, no matter where on Earth you happen to be.

In the Northern hemisphere, the Sun travels its lowest, shortest path across the sky on that day. Thus, in the north, the winter solstice brings the shortest day of the year, in terms of hours of sunlight.

Now the Sun's changing height in the sky throughout the year is caused by Earth's tilt as it orbits our local star. The tilt causes the amount of sunlight each hemisphere receives to go up and down in the annual cycle of the seasons.

The night sky is always a celestial showcase. Explore its wonders from your own backyard.

The following Deep Sky Objects are found in constellations that peak during the month. Some can be viewed with a small telescope, but the majority will require a moderate to large telescope. The following is adapted from my personal viewing list: "The Guy Pirro 777 Best and Brightest Deep Sky Objects."


Constellation: Camelopardalis

IC 342                          Galaxy                         C5

IC 356                          Galaxy                         P127

IC 361                          Open Cluster               P213

IC 3568                        Planetary Nebula          P128

NGC 1501                    Planetary Nebula           Herschel 400 H53-4

NGC 1502                    Open Cluster               Herschel 400 H47-7

NGC 1708                    Open Cluster               P129

NGC 1961                    Galaxy                         Herschel 400 H747-3

NGC 2146                    Galaxy                         P130

NGC 2336                    Galaxy                         P70

NGC 2403                    Galaxy                         C7, Herschel 400 H44-5

NGC 2408                    Open Cluster               P131

NGC 2655                    Galaxy                         Herschel 400 H288-1


Constellation: Cassiopeia

IC 10                            Galaxy                        P77

IC 59                           Diffuse Nebula              P21 - Gamma Cassiopeiae Nebula (West)

IC 63                            Diffuse Nebula             P22 – Gamma Cassiopeiae Nebula (East)

IC 166                          Open Cluster               P217

IC 1795                        Diffuse Nebula              P122

IC 1805                        Emission Nebula           P2 Heart Nebula

IC 1848                        Emission Nebula           P3 Soul Nebula

IC 1871                        Diffuse Nebula              P136

NGC 103                      Open Cluster                P137

NGC 129                      Open Cluster                Herschel 400 H79-8

NGC 133                      Open Cluster                P138

NGC 136                      Open Cluster                Herschel 400 H35-6

NGC 146                      Open Cluster                P204

NGC 147                      Galaxy                         C17 Satellite of Andromeda

NGC 185                      Galaxy                         C18, Herschel 400 H707-2 Satellite of Andromeda

NGC 189                      Open Cluster                P5

NGC 225                      Open Cluster                Herschel 400 H78-8 Sailboat Cluster

NGC 278                      Galaxy                         Herschel 400 H159-1

NGC 281                      Emission Nebula            P4 Pacman Nebula

NGC 381                      Open Cluster                Herschel 400 H64-8

NGC 436                      Open Cluster                Herschel 400 H45-7

NGC 457                      Open Cluster                C13, Herschel 400 H42-1 Owl Cluster

NGC 559                      Open Cluster                C8, Herschel 400 H48-7

NGC 581                      Open Cluster                M103

NGC 609                      Open Cluster                P219

NGC 637                      Open Cluster                Herschel 400 H49-7

NGC 654                      Open Cluster                Herschel 400 H46-7

NGC 659                      Open Cluster                Herschel 400 H65-8

NGC 663                      Open Cluster                C10, Herschel 400 H31-6

NGC 1027                    Open Cluster                Herschel 400 H66-8

NGC 7635                    Diffuse Nebula              C11 Bubble Nebula

NGC 7654                    Open Cluster                M52

NGC 7788                    Open Cluster                P139

NGC 7789                    Open Cluster                Herschel 400 H30-6 White Rose Cluster

NGC 7790                    Open Cluster                Herschel 400 H56-7

NGC 7795                    Open Cluster                P23


Constellation: Cepheus

Caldwell 9                   Diffuse Nebula               C9 Cave Nebula

IC 1396                        Open Cluster              P6 Elephant Trunk Cluster

NGC 40                        Planetary Nebula          C2 Herschel 400 H58-4 Bow Tie Nebula

NGC 188                      Open Cluster               C1

NGC 2300                    Galaxy                        P220

     - NGC 2276             Galaxy                              - Paired with P220

NGC 6939                    Open Cluster               Herschel 400 H42-6

NGC 6946                    Galaxy                        C12, Herschel 400 H76-4 Fireworks Galaxy

NGC 7023                    Open Cluster                C4 Iris Nebular Cluster

NGC 7142                    Open Cluster                 Herschel 400 H66-7

NGC 7160                    Open Cluster                 Herschel 400 H67-8

NGC 7226                    Open Cluster                 P140

NGC 7235                    Open Cluster                 P7

NGC 7261                    Open Cluster                 P8

NGC 7380                    Open Cluster                 Herschel 400 H77-8

NGC 7510                    Open Cluster                 Herschel 400 H44-7

NGC 7762                    Open Cluster                 P141


Constellation: Eridanus

IC 1898                        Galaxy                         P228

NGC 1084                    Galaxy                         Herschel 400 H64-1

NGC 1232                    Galaxy                         P28

NGC 1291                    Galaxy                         P29

NGC 1300                    Galaxy                         P81

NGC 1332                    Galaxy                         P82

NGC 1407                    Galaxy                         Herschel 400 H107-1

NGC 1535                    Planetary Nebula           Herschel 400 H26-4

NGC 1537                    Galaxy                         P229 


Constellation: Perseus

IC 348                          Open Cluster               P95

IC 2003                        Planetary Nebula          P237

NGC 650                      Planetary Nebula          M76 Little Dumbell Nebula

NGC 651                      Planetary Nebula          Herschel 400 H193-1 Part of M76

NGC 744                      Open Cluster               P96

NGC 869                      Open Cluster               C14a, Herschel 400 H33-6 Double Cluster (West)

NGC 884                      Open Cluster               C14b, Herschel 400 H34-6 Double Cluster (East)

NGC 957                      Open Cluster               P97

NGC 1023                    Galaxy                        Herschel 400 H156-1

NGC 1039                    Open Cluster               M34 Spiral Cluster

NGC 1220                    Open Cluster               P238

NGC 1245                    Open Cluster               Herschel 400 H25-6

NGC 1275                    Galaxy                        C24 Perseus A Seyfert Galaxy

NGC 1342                    Open Cluster               Herschel 400 H88-8

NGC 1444                    Open Cluster               Herschel 400 H80-8

NGC 1496                    Open Cluster               P174

NGC 1499                    Diffuse Nebula             P44 - California Nebula

NGC 1513                    Open Cluster               Herschel 400 H60-7

NGC 1528                    Open Cluster               Herschel 400 H61-7

NGC 1545                    Open Cluster               Herschel 400 H85-8

NGC 1582                    Open Cluster               P45

NGC 1605                    Open Cluster               P239

NGC 1624                    Open Cluster               P240


Constellation: Taurus

Messier 45                  Open Cluster               M45 Pleiades

Caldwell 41                 Open Cluster               C41 Hyades

IC 1995                        Diffuse Nebula           P64

NGC 1514                    Planetary Nebula         P120

NGC 1554                    Diffuse Nebula            P200 Von Struve’s Lost Nebula

NGC 1555                    Diffuse Nebula            P201 Hind’s Variable Nebula

NGC 1647                    Open Cluster               Herschel 400 H8-8

NGC 1750                    Open Cluster               Herschel 400 H43-8

NGC 1807                    Open Cluster               P65

NGC 1817                    Open Cluster               Herschel 400 H4-7

NGC 1952                    Diffuse Nebula              M1 Crab Nebula


Constellation: Ursa Major

Messier 40                  Double Star                 M40 Winnecke 4

IC 2574                        Galaxy                         P121 Coddington’s Dwarf Galaxy

NGC 2681                    Galaxy                         Herschel 400 H242-1

NGC 2742                    Galaxy                         Herschel 400 H249-1

NGC 2768                    Galaxy                         Herschel 400 H250-1

NGC 2787                    Galaxy                         Herschel 400 H216-1

NGC 2841                    Galaxy                         Herschel 400 H205-1

NGC 2950                    Galaxy                         Herschel 400 H68-4

NGC 2976                    Galaxy                         Herschel 400 H285-1

NGC 2985                    Galaxy                         Herschel 400 H78-1

     - NGC 3027             Galaxy                              - Paired with H78-1

NGC 3031                    Galaxy                         M81 – Bode’s Galaxy

NGC 3034                    Galaxy                         M82, Herschel 400 H79-4 Cigar Galaxy

NGC 3077                    Galaxy                         Herschel 400 H286-1

NGC 3079                    Galaxy                         Herschel 400 H47-5

NGC 3184                    Galaxy                         Herschel 400 H168-1

NGC 3198                    Galaxy                         Herschel 400 H199-1

NGC 3310                    Galaxy                         Herschel 400 H60-4

NGC 3556                    Galaxy                         M108 Herschel 400 H46-5

NGC 3359                    Galaxy                         P202

NGC 3587                    Planetary Nebula        M97 Owl Nebula

NGC 3610                    Galaxy                         Herschel 400 H270-1

NGC 3613                    Galaxy                         Herschel 400 H271-1 Paired with H244-1

NGC 3619                    Galaxy                         Herschel 400 H244-1 Paired with H271-1

NGC 3631                    Galaxy                         Herschel 400 H226-1

NGC 3665                    Galaxy                         Herschel 400 H219-1

     - NGC 3658             Galaxy                              - Paired with H219-1

NGC 3675                    Galaxy                         Herschel 400 H194-1

NGC 3726                    Galaxy                         Herschel 400 H730-2

NGC 3729                    Galaxy                         Herschel 400 H222-1

     - NGC 3718             Galaxy                              - Paired with H222-1

NGC 3813                    Galaxy                         Herschel 400 H94-1

NGC 3877                    Galaxy                         Herschel 400 H201-1

NGC 3893                    Galaxy                         Herschel 400 H738-2

     - NGC 3896             Galaxy                              - Paired with H738-2

NGC 3898                    Galaxy                         Herschel 400 H228-1

NGC 3938                    Galaxy                         Herschel 400 H203-1

NGC 3941                    Galaxy                         Herschel 400 H173-1

NGC 3945                    Galaxy                         Herschel 400 H251-1

NGC 3949                    Galaxy                         Herschel 400 H202-1

NGC 3953                    Galaxy                         Herschel 400 H45-5

NGC 3982                    Galaxy                         Herschel 400 H62-4

NGC 3992                    Galaxy                         M109, Herschel 400 H61-4

NGC 3998                    Galaxy                         Herschel 400 H229-1

     - NGC 3990             Galaxy                              - Paired with H229-1

NGC 4026                    Galaxy                         Herschel 400 H223-1

NGC 4036                    Galaxy                         Herschel 400 H253-1 Paired with H252-1

NGC 4041                    Galaxy                         Herschel 400 H252-1 Paired with H253-1

NGC 4051                    Galaxy                         Herschel 400 H56-4

NGC 4085                    Galaxy                         Herschel 400 H224-1 Paired with H206-1

NGC 4088                    Galaxy                         Herschel 400 H206-1 Paired with H224-1

NGC 4102                    Galaxy                         Herschel 400 H225-1

NGC 4605                    Galaxy                         P252

NGC 5322                    Galaxy                         Herschel 400 H256-1

NGC 5457                    Galaxy                         M101 Pinwheel Galaxy

NGC 5474                    Galaxy                         Herschel 400 H214-1 Paired with M101

NGC 5473                    Galaxy                         Herschel 400 H231-1

NGC 5631                    Galaxy                         Herschel 400 H236-1


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