T Coronae Borealis: still waiting

 T Coronae Borealis, aka the "Blaze Star" or T CrB, is a recurrent nova with a period of approximately 80 years.  The last observed eruption was in 1946.  However, based on the brightness variations observed previous to the last outburst, the next eruption is expected in 2024 rather than 2026.  

Corona Borealis setting over Bristol Head.  E-M5iii + Sigma 56m f/1.4 + softon filter.

The position of T CrB is marked by the white circle in the image above.  When it erupts it should be roughly equal in brightness to Alphecca (Alpha Coronae Borealis), the brightest star in this image.

The sky brightness was mediocre for Creede, with sqml=21.15.  There were a lot of clouds in the sky, with some thin murky cover.

As usual, click on an image to get into Gallery View, from which you can download or view the full-size image.

Farewell to the summer MIlky Way

Viewing time for the densest part of the Milky Way is rapidly dwindling as autumn advances.  Last night appeared to be clear, but the sky brightness was a mediocre (for Creede) sqml=21.15.  There may have been a layer of thin clouds that was not easy to see.  Some airglow is visible in the long exposures (60 s), but it does not appear to be the cause.

Images were obtained with an Olympus E-M1iii + Rokinon 12mm f/2 lens + Hoya Sparkle-6 filter.

Sagittarius setting over Bristol Head.

Vega over Bristol Head

Vega is the fifth brightest star, just behind Arcturus.

Posted from a Raspberry Pi 4B running Ubuntu Linux, just for the fun of it.

UFO in the sky over Creede

 There were some moments of surprise and confusion this morning.  There was a bright "star" in the east suspended over the ridgeline of Snowshoe Mountain.  But, it wasn't rising, it was moving in the opposite direction.  Binoculars revealed a double-lobed shape.  Some internet searching, conducted after a 40 min power outage, revealed that this was likely a Gryphon Stratollite balloon manufactured by World View Enterprises.  Colorado news outlets report that it is flying a scientific mission for NASA.

World View has not published (that I could find) the dimensions of the balloon assembly.  However, they state that the upper balloon has a nominal volume of 23,000 m³.  Assuming a spherical volume (crude approximation), this works out to a diameter of about 35 m.  From the measured angular dimensions and elevation above the horizon, the estimated distance was about 55 mi (89.5 km) and height was about 62,000 ft (19 km) (with large uncertainty).

AT60mm ED f/6 telescope + Olympus E-M5iii camera.

First taste of winter

 When the clouds parted briefly on Saturday (21 Sep), the La Garitas were blanketed with white.

Bristol Head.  22 Sep.

Harvest moon setting

 The waning Harvest moon this morning (20 Sep) was three days past full.  It set below the Bristol Head ridgeline at 8:49 am, sinking into the golden aspens.

Harvest Super-Moon partial eclipse

 The September full Moon is traditionally called the Harvest Moon.  This year it is also a so-called "Super Moon" (perigean full moon).  And, bonus, there was a partial, mostly penumbral, lunar eclipse.  

The eclipse was in progress as the Moon rose over Snowshoe Mountain on Tuesday (17 Sep) night:

8:35 pm MDT

Mid-eclipse occurred shortly afterward:

Mid-eclipse. 8:44 pm MDT.

This sequence spans about 50 minutes:

All images were obtained with an Apertura 60mm ED f/6 refractor and an Olympus E-M5iii camera.

Observing the Moon (and Sun, and stars)

 Last night, Saturday 14 September, was a NASA-sponsored "International Observe the Moon Night".  According to NASA, this is an annual event chosen to occur in the fall on a weekend (i.e., Saturday) near the time of a quarter-Moon.  Why a quarter Moon? - because that is when crater detail is most easily visible.  The Astronomical League also publicizes two annual "Astronomy Days" (one in Spring, one in Fall) that are timed to the quarter-moon for the same reason.  On Saturday the moon age was 11.4 days, about 4 days past quarter phase.

Celestron C5 + E-M5iii, ISO 320, 1/320 s.

Here is a close-up of the northern region:

The dark oval near the center is the crater Plato.

Friday, 13 September.  C5 + E-M5iii. ISO 320, 1/200 s.

This image of the double star Albireo was also obtained with the Celestron C5 on Friday night:

Celestron C5.  ISO 400, 2 s.

Albireo (Beta Cygni) is probably an optical double, i.e., a chance alignment, rather than two gravitationally-bound stars.  Regardless, the contrasting colors of the two stars make it a worthwhile sight in small telescopes.

Unlike the moon, features on the sun can change over time-scales ranging from minutes to days.  There have been some interesting prominences visible the past few days:

13 September.  Lunt LS50THa double-stack.

14 September.

Some close-ups:

Looking straight up

The sky was clear, so I felt obligated to take some pictures.  The camera was an Olympus E-M5III and the lens was a Laowa 7.5mm f/2.  These images were obtained from the front of the house, because the clueless backyard AirBnB neighbors had the porch lights blazing all night. WTF!? (invective mostly suppressed).  Sky brightness: sqml=21.35 mpsas.

The Summer Triangle, straight up at 10 pm MDT.  Sparkle-6 filter.

Arcturus and the Big Dipper setting over Bristol Head.

The Milky Way emerging from the murky southern airglow.

First day of September

Sunday 1 September, was the day before the official Labor Day holiday on Monday.  The sky was mostly clear, but not impressively dark.  The measured brightness was sqml=21.15 mpsas.  No significant airglow showed up on camera, so the cause is a mystery.

The following images were obtained with a Sony A7iii + Rokinon AF 24mm f/1.8 lens.

Milky Way with storm clouds on the horizon. Sparkle-6 filter.

The Summer Triangle directly overhead: Deneb, Vega, Altair.  Softon filter.

The end of August

 August 30, so not quite the end, but close enough.  All photos, except for the last one, were obtained with an Olympus E-M5iii + Sigma 56mm f/1.4 lens.

Corona Borealis.  Still waiting for the recurrent nova T CrB to appear.  Softon filter.

Arcturus setting over Bristol Head. Softon filter.

Scorpius setting over the Bristol Head ridgeline.  Softon filter.

The heart of the Milky Way.  Softon filter.

Milky Way standing tall.  Leica 9mm f/1.7 + sparkle-6 filter.