December full moon

 The traditional name for the full moon of December is the "Cold Moon".  Full moon occurred near 2 am MST on 15 Dec.  These images were taken more than 15 hr later with an AT72EDII refractor (432mm FL, f/6).

Cold Moon rising over the Sangre de Cristo mountains.

Four hours later, above the clouds:

Jupiter is the second brightest object in the sky at this hour.

Jupiter (overexposed) and its Galilean moons (from LL):  Callisto, Europa, Io, Ganymede.

The four Galilean moons can be seen with very modest equipment.  I was able to spot them easily with a tripod-mounted 50-mm refractor at 10 x.  Twenty power (20 x) is enough to see not only the moons but the disc of Jupiter as well.  The moons should be visible with a 7x50 binocular if the instrument is on a stable mount.  I tried to spot them hand-held, but there is too much shake.  The telescope that Galileo used was a 20x30mm refractor (20 power, 30 mm diameter).

Another look at the seventh planet. Trying out a new "filter".

 Now is a good time to look for the seventh planet, Uranus.  It is about as bright as it ever gets, and it is near a celestial landmark, the Pleiades, which makes it relatively easy to find.

Uranus was discovered to be a planet by the English astronomer William Herschel in 1781.  He gave it the name "Georgium Sidus".  It wasn't until 1850 that its present name, Uranus, became universally accepted.

The Pleiades (left) and Uranus (white circle).  Olympus E-M5iii + Sigma 56mm f/1.4 + softon filter.  ISO 800, 15 s at f/2.8.

Uranus was easily visible in 6x30 binoculars, but not with a 1.8x40 wide-field binocular.  City lights and the quarter moon were too much for the low-power instrument to overcome.

The new "filter" that was tried was the Omegon cross-star plate for the Seestar S50.  It consists of two crossed wires.  The effect mimics the diffraction pattern created by the typical four-vaned secondary-mirror support of Newtonian and Cassegrain-type reflectors.

The Pleiades with the Omegon cross-star filter.

Hoya Softon-A filter.

No filter.

Omegon cross-star filter.

Aldebaran and the Hyades cluster.  Cross-star filter.

Softon filter.

The sky brightness was not measured for this session.  The quarter-moon was still high in the sky and there appeared to be a thin cloud layer.

Moon, Venus, Jupiter, Uranus

Back in Santa Fe for the winter.

 Venus, at magnitude -4.2, is the second brightest object in the night sky , after the moon.  Both have been close together recently in evening twilight.

Moon and Venus.  05 Dec.  E-M5iii + Sigma 56mm f/1.4

The third brightest object in the night sky is Jupiter.  Jupiter is near opposition, meaning that it crosses the meridian around midnight.  It currently shines at magnitude -2.8.

Jupiter, the Hyades, and Pleiades.  The white circle is centered on Uranus.  Lumix 20mm f/1.7 lens, softon filter.

The planet Uranus is near the Pleiades and shines at magnitude 5.6.  This means it should technically be visible to the unaided eye at a dark-sky location.  That would rule out urban Santa Fe, which had a sky brightness of sqml=19.75 last night.  It should be easy to find with binoculars, however.  I was able to spot it with a 6x30 binocular, an 8x32 monocular, and a 7x50 binocular.

Orion rising and Cygnus setting

These images were processed somewhat differently than normal.  The intent was to reproduce the visual experience rather than show the faintest stars.  Watching Orion rise over the mountains in a clear dark winter sky is an inspiring sight.

Orion rising over McCall Gulch. 22 Sep, 9:42 pm.  Samyang AF 24mm f/1.8, sparkle-6 filter.

 The brightest "star" in this image is Jupiter, top left center.  At mag -2.8, it is the fourth brightest object in the sky, after the sun, the moon, and Venus.

Here is the same view, but with a different filter (Hoya Softon-A):

Orion and Sirius rising over McCall Gulch.  Leica 15mm f/1.7.  Sparkle-6 filter.

Softon filter.

Cygnus setting over Bristol Head.  Leica 15mm f/1.7, Sparkle-6 filter.

Mars and the Beehive Cluster (M44) rising over Snowshoe Mtn.  75mm f/1.8.

Testing an old lens, just for fun. Comet C/2023 A3 is still there.

A clear night before moonrise provided an opportunity to try out an old lens: a manual-focus Phoenix 19-35mm f/3.5-4.5 zoom lens with Olympus OM mount.  This was designed for 35mm format ("full frame") and was purchased new in 2008.  It is not an ideal choice for astrophotography because of the slow aperture, but it seems to perform surprisingly well for daytime photography (with some easily corrected lateral chromatic abberation), so I wanted to see how it would do at night.  "Phoenix" is a marketing brand-name.  According to speculation in old camera-forum posts, the OEM for this lens was probably the Japanese optical company Cosina.

The lens was mounted with an adapter on a Sony A7iii camera.

19mm f/3.5 with Sparkle-6 filter. 6:34 pm MST.

In this image, Venus is the bright star in the lower left corner, setting over the ridgeline of Bristol Head.  The bright stars Altair (left) and Vega (right) are just above center.  Some bands of red and green airglow cross the middle and lower portion of the frame.

If you know where to look, Comet C/2023 A3 is still visible.  The white circle in the next image shows the location.  I was able to see it as a faint smudge with 10x50 binoculars.  It is currently magnitude 8+ and fading.

The white circle marks the location of comet C/2023 A3.

A longer-focal-length lens provides a better view:

Comet and airglow.  Olympus E-M1iii  + 75mm f/1.8 lens.

The comet is in the upper left of the frame.  The star cluster in the center is IC 4756, and the cluster to the lower right is NGC 6633.

view toward the NW.  19mm f/3.5 + sparkle-6 filter.

The measured sky brightness after these images were taken was sqml=20.9 to the north and 21.1 to the south.

More November star trails and solar prominences

 

2 hr.  E-M1iii + Leica 9mm f/1.7

11:17 am

November full moon, rising and setting

 The full moon of November is traditionally called the "Beaver Moon".  This year it is also a so-called "supermoon", because it becomes full when the moon is near perigee (closest to Earth). The term supermoon is largely meaningless and mostly serves for news-media click-bait purposes.  This November full moon has an apparent size of 33.2' (arcmin).  The December full moon, which does not meet the arbitrary "supermoon" definition, will have an apparent size of 32.6', only 1.8% smaller. Meaningless.

Moonrise over Snowshoe Mtn. 15 November, 6:41 pm MST.

6:42 pm

Moonset over Bristol Head.  16 November, 6:34 am MST.

16 November, 7:21 am MST.

Setting over Bristol Head. 7:42 am MST

7:43 am