Creede Dark Skies: August star fields

Clear moonless nights have been rare so far this month. Last night over half the sky was still covered by clouds during early twilight. Later in the evening it was clear and calm with a measured sky brightness of sqml=21.49.

Arcturus is the brightest star in the western sky in the late evening, hanging low over Bristol Head. Above Arcturus is the constellation Corona Borealis. This semi-circle of stars is the location of the recurrent nova T Coronae Borealis, also known as T CrB or the "Blaze Star". Based on its behavior prior to previous outbursts in 1866 and 1946, this nova is expected to erupt "any time now" (roughly, every 80 years). Current predictions are for November of this year or June of 2026. In its normal state the star requires a small telescope to be seen. When it erupts it will likely be similar in brightness to Alphecca, the brightest star in Corona Borealis.

The following images were obtained with an Olympus E-M1iii + Sigma 56mm f/1.4 lens + Hoya Softon filter.

Corona Borealis. T CrB is circled.

The constellation Cepheus lies on the edge of the northern Milky Way and is the location of a star of cosmological importance: Delta Cephei. This star was one of the first identified of the class of variable stars now known as "Cepheids". The pulsation periods of these stars are directly related to their intrinsic brightness, and the distance to this type of star can thus be inferred simply by measuring its period. Observations of these stars provided the first measurements of the distance to other galaxies and helped establish our knowledge of the scale of the universe.

Delta Cephei is circled.

The orange star top center in this image is Mu Cephei, also known as the "Garnet Star". It is one of the largest and most luminous stars in our galaxy.

Another significant Cepheid variable is Eta Aquilae. It was first recognized as a variable star about the same time as Delta Cephei. Both of these stars are nearly the same distance from us at about 900 ly.