What to observe in the sky in December 2025 with a smart telescope.
30 Nov. 2025
December 2025 astronomical calendar
It is recommended to observe nebulae and galaxies when the Moon is not visible. Its brightness diminishes the darkness of the sky and reduces the quality of observations of faint and diffuse objects.
Refer to the following calendar for the best days this month.
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December 3–4 — The Moon passes through the Pleiades
Best seen on the evening of the 3rd in the USA and on the morning of the 4th in Europe. -
December 5 — Full Moon
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December 11 — Last Quarter Moon
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December 14 — Geminid Meteor Shower Peak
(30–40 meteors per hour) -
December 15 — Best period to observe the nebulae in Orion
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December 18 — Start of galaxy season in the Northern Hemisphere
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December 19 — New Moon
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December 21 — December Solstice: The longest night in the northern hemisphere and the shortest in the southern hemisphere.
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December 27 — First Quarter Moon
Celestial Scene of the Month
Northern sky
Christmas Tree cluster, Cone and Fox Fur Nebula
Just east of Orion’s Belt, in the constellation Monoceros, lies a group of objects that are in fact different faces of the same star-forming complex.
The Christmas Tree Cluster (NGC 2264) appears as a loose, sparkling group of young blue-white stars, bathing in a red ionized hydrogen (H II) region whose shape resembles a Christmas tree. At the top of the tree, a dark triangular cloud carves into the glowing red background : The Cone Nebula
At the center of the tree sits a small reflection nebula: the Fox Fur Nebula. The entire region is enveloped by vast hydrogen clouds that extend far beyond the field of view.
There are several ways to observe this scene:
- With a dual-band filter, the emission zones stand out strongly, and the Cone Nebula becomes striking by contrast. However, the Fox Fur Nebula will not appear, and you will also lose the blue tones of the cluster’s stars.
- Without the dual-band filter, the Fox Fur becomes visible, and the blue starlight is preserved, but much of the red H II emission fades into the dense starfield—though the Cone Nebula remains clearly visible.
Southern sky
Vela molecular ridge
You're about to explore a region that have mostly been out of the scope of smart telescope so far : the large Vela supernovae remnant and Gum nebula that spread across the Vela and Puppis Constellation.
The part we propose to focus on is a chain of hydrogen clouds crisscrossed by dark nebulae: The Vela Molecular Ridge. It is one of the nearest star-forming complex.
In itslef it spread over 8° so we can frame only the most interesting part : Gum 14, Gum 15 (the most compact and brightest) and Gum 17 clouds.
Not being listed in the classical astronomical catalogs ( NGC or IC) those targets are not visible in the Singularity mosaic framing interface. Fortunately, there's a small star cluster, NGC2671, that we can use to frame our mosaic. You need to create a manual target with this star cluster. Read the Vespera Guidebook p. 62 to learn everything about manual targets.
You'll find at the bottom of this article a map of the Vela Supernovae Remnant region that will helps you locating the various targets. Gum 14,15 and 17 are the most prominent green shapes near the center of the map. NGC2671 star cluster is the yellow circle between Gum 15 and Gum 17.
Dual band filter is recommended for this observation.
On the view below, the green circles have been added for more convenience yet are not present in Singularity mosaic mode interface.
"Plan my Night" of the month
Suggested observation program you can automate with "Plan My Night."
Give each object as much observation time as you can to get the best results.
Northern sky
Do not use a dual band filter (mix of object type)
| Time | Target |
|---|---|
| Early Night |
Wizard Nebula ( NGC 7380) |
| Mid Night |
Horsehead Nebula |
| Late Night |
M81 & M82 galaxies |
Southern sky
Using dual band filter is an option
| Time | Target |
|---|---|
| Early Night |
The Orion Nebula,M42 |
| Mid Night |
Seagull Nebula (IC 3177) |
| Late Night |
Pencil Nebula (NGC 2736, RCW37) + Gum 22 Nebula (RCW38) |
Around the full moon
During the few nights surrounding the full moon, it's best to focus on star clusters, which are less affected by the Moon’s light pollution.
Northern sky
Messier 38 : open cluster in Auriga constellation. Magnitude 6.4
Southern sky
Caldwell 71 & NGC 2451 : Two open clusters in Puppis that you can get in the same field of view with mosaic mode. Magnitude 5.8 & 2.8.
Challenging Target of the Month
Taurus molecular cloud
Visibility: Northern hemisphere
Constellation: Taurus
Type: Mainly dark nebulae with some tiny reflection nebulae
Between the constellations Taurus and Auriga stretches a vast tangle of dense, filamentary dark molecular clouds, from which small reflection nebulae occasionally emerge. Located only a few hundred light-years away, this is one of the closest star-forming regions to Earth.
The complex is so large that it would take multiple mosaics to cover it entirely. However, several areas are particularly interesting and worth focusing your observations on. Here are two of them:
Barnard 7, Barnard 10 & LBN 782 Region
A chaotic field where the dark filaments B7 and B10 snake across the sky, mingling with the blue reflection nebulae LBN 782, LBN 785, and even a background galaxy (IC 359) peeking through.
Since this region does not appear in the Singularity catalog, you must create a manual target using the following coordinates:
RA: 04h 17m 24s
DEC: +28° 08′ 00″
Set a square mosaic at maximum size.
Do not use any filter.
Barnard 22 & IC 2087
B22 is a large, dense dark cloud, while IC 2087 is a tiny reflection nebula embedded within it, appearing as a flame-like knot of light in a sea of darkness.
Create a manual target with the coordinates below to center it perfectly:
RA: 04h 40m 10s
DEC: +25° 45′ 00″
Do not use any filter.
Vela supernovae remnant
Visibility: Southern hemisphere
Constellation: Vela
Type: Supernovae remnant & emission nebula
The Vela Supernova Remnant (Vela SNR or SNR G263.9–03.3) is a vast cloud of debris left behind by a supernova that exploded about 11,000 years ago. It is similar in nature to the Veil Nebula in Cygnus, but far larger, panning nearly 8° across the constellations Vela and Puppis (see the star chart below).
At its center lies the Vela Pulsar, a rapidly spinning neutron star that provides direct evidence that the explosion left behind an ultra-compact stellar remnant.
What you can observe are shock waves sweeping through the interstellar medium, illuminating filaments of ionized hydrogen and oxygen. The entire structure appears in the foreground of a gigantic H II region: the Gum Nebula (Gum 12).
Because of its enormous size, it is impossible to capture the full remnant in a single Vespera field of view, even in Mosaic Mode. This creates multiple framing opportunities, and you may even attempt a mega-mosaic.
One of the most interesting regions lies just south of the Vela Molecular Ridge.
Here is a suggested area to observe:
Create a manual target using the following coordinates:
RA: 08h 34m 20s
DEC: –42° 52′ 17″
A dual-band filter is recommended for this observation.
Star chart of the Vela supernova remnant and Vela molecular ridge region. Credits : Roberto Mura / Wikipedia (cc)
Magnitude and angular size reminder
