Monday evening twilight. The 3.2-d crescent moon and Venus were eye-catching above the southern flank of Bristol Head as the late-afternoon clouds dissipated.
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| Sony A7iii + Nikon 180mm f/2.8 Ai-s. |
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| Olympus E-M1iii + Olympus 75mm f/1.8. |
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| Comet C/2023 A3 and a meteor. Olympus 75mm f/1.8. |
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| 75mm f/1.8 |
The comet is still there, but getting fainter. It can be seen with binoculars, but that will become harder as the moon gets brighter.
This morning clocks reverted to Standard Time. When I stepped out onto the back porch at 5:30 am (MST) to grab some firewood I spooked a deer. I also noticed that stars were visible in spite of some clouds low to the horizon.
Jupiter currently rules the late evening and early morning sky. At magnitude -2.7 it is 3.3 times brighter than Sirius.
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| Orion and Jupiter over Bristol Head. E-M1iii + Leica 9mm f/1.7 lens. |
Venus is now the "Evening Star". It is currently the brightest planet, at magnitude -4.
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| Venus, 31 Oct. Olympus 50mm f/2 ED |
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| Barnard's Star (circled). 01 Nov, 7:50pm MDT. Nikon 180mm f/2.8 Ai-s. |
Barnard's Star is 6 ly distant and has the largest proper motion (movement relative to the more distant background stars) of any known star (10.3 arcsec/year). It is getting some attention because of the close pass by comet C/2023 A3. Barnard's Star is more than twice as old as our sun, and will live much longer, over a trillion years.
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| Our star, the Sun. 01 Nov. AT102ED f/7 + Lunt solar wedge. |
The sun is near the peak of the current solar cycle, with many active sunspots.
A clear night is hard to resist, and I wanted to try out another lens. Comet C/2023 A3 is no longer visible to the unaided eye, and in fact it took some effort to find with binoculars. It is no longer the spectacle it was less than a week ago. The sky brightness was sqml=21.0 at the time of this image. Camera: Olympus E-M1iii + Olympus 50mm f/2 ED macro lens.
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| Comet C/2023 A3, Halloween night, 8:13 pm MDT |
In addition to the comet, there are a lot of other interesting objects in this field of view. The same image is presented below with some labels added.
The three circled star clusters range from about 1200 to 1600 light years distant.
To the right of the comet is Barnard's Star. At a distance of just 6 light years, this star is the second closest to our sun after the three-star Alpha Centauri system. It is a red-dwarf star with an estimated lifetime of over a trillion years.
Here are a couple cropped views:
As usual, click on any image to enter Gallery View, then right-click to get at the full-size version.
This image is from Saturday night, 26 Oct. There was a thin cloud or haze layer that acted as a natural diffusion filter, causing a halo around the brighter stars. The sky brightness was about sqml=21.1. The comet was just at the limit of visibility to the unaided eye. It is still a fine view with binoculars or a small telescope.
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| Comet C/2023 A3, star cluster IC4665, and Barnard's Star (white circle) |
The comet's tail in this image exceeds 5 degrees. The star in the center is mag-2.8 Cebalrai, Beta Ophiuchus. Just above that is the star cluster IC 4665. In the upper left a white circle marks the position of mag-9.5 Barnard's Star, which appears as a reddish dot in the full-size image. At a distance of 6 light years, this star is the second closest to our sun after the Alpha Centauri system.
The range of distances in this image remarkable:
Another faint star of interest is T Corona Borealis, the "Blaze Star", a recurrent nova that is expected to erupt imminently. Unfortunately, if it doesn't happen soon we may miss it. In just a few weeks this constellation will be too low in the western sky as twilight fades.
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| Corona Borealis |
The location of T CrB is marked with a white circle in this image. Its normal brightness is magnitude 10.1. When it erupts it is expected to be about as bright as Alphecca, the brightest star in this image.
Both of the above images were obtained with an Olympus E-M5iii + Olympus 75mm f/1.8 lens.
Not much new to say. Another night of mediocre darkness, sqml=21.07. Same comet, it's fading, but still fun to observe with optical aid. I used 1.8x40 and 10x50 binoculars, and a 60mm f/6 telescope with an 18.2 mm eyepiece (20 x).
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| 8:37 pm MDT. Leica 15mm f/1.7 lens + softon filter. |
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| 8:42 pm MDT. Comet (left) and Coma Berenices (right) setting over Bristol Head. |
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| 8:16 pm MDT. Olympus 75mm f/1.8 lens. |
The tail extends over 5 degrees.
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| Venus setting. Still fun to watch. Olympus 75mm f/1.8 |
These pictures of comet C/2023 A3 are becoming repetitive, so this may be the last set in spite of continuing clear skies. The comet is still visible to the unaided eye as a faint smudge to the right of the Milky Way. It is also still impressive in binoculars.
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| 8:36 pm 23 Oct. Olympus E-M1iii + Leica 9mm f/1.7 + sparkle-6 filter |
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| 8:23 pm MDT. E-M1iii + Sigma 30mm f/1.4 + softon filter |
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| 8:04 pm MDT. Sony A7iii + Nikon 180mm Ai-s f/2.8 ED. |
This next image is an alternate version of the first one, with the contrast left open to show the extent of airglow in the western sky. A vehicle traveling on Highway 149 was lighting up the flank of Bristol Head during this exposure.
