Waiting for T Coronae Borealis

Things change in the sky. Contrary to the stenuous assertions of some, the night sky is not constant, it changes. Stars move, sometimes fairly rapidly, stars fade, and sometimes brighten dramatically.

Then there are novae, stars the flare to a brilliance far beyond their normal lustre. Such a star is T Coronae Borealis, or T CrB for short. This star is a recurrent nova, a star that flares to brilliance once or twice every century.

Sometimes called the Blaze Star, T CrB is normally a dim 10th magnitude star, a star that requires a small telescope to view, lost in a field filled with similar stars. A few times in the annals of astronomy the star has blazed to second magnitude, about 1500 times brighter. In 1866 and 1946 the star rivaled nearby Alphecca, the brightest star in the constellation of Corona Borealis. It may also have been observed in 1217 and again in 1787 giving a rough period of about 80 years.

T CrB is a white dwarf that is stealing material from a stellar companion, a red giant near the end of its own fuel. When that material builds up enough the white dwarf flares into temporary brilliance as a fusion reaction tears across the surface of the stellar remnant. The cycle repeats over the centuries causing these regular novae. Eventually the accumulating mass will be too great and instead of a recurring nova the star will meet its final end as a type Ia supernova.

I am of course among those awaiting the eventual nova. Yesterday evening I took a few images of the field to capture the scene. Hopefully I can take the images again to get a before and during image of T CrB.

Last year T CrB started exhibiting behavoirs similar to what had been measured just prior to the 1946 eruption. As a result we expect the star to go nova on schedule this year, most likely in the next month.

We have been waiting, stargazers keeping an eye on the constellation all summer.

Not yet.

Awaiting the recurring nova of T CrB
T CrB on the evening of 22 Aug 2024… Still about 10th magnitude, no nova yet. The 4th magnitude star Epsilon CrB at the top.

A Better Sun…

After yesterday’s unsatisfactory image of the Sun I set out to do it right today.

The conditions were about the same, the telescope and camera the same, but no clouds cutting short my time at the camera. I took a few video segments and processed these with AutoStakkert! to produce a stack of the best 900 frames out of 1800. The result is a much better image.

The image is more representative of what you see at the eyepiece, with somewhat more detail visible to the eye. These active sunspots have been the source of strong flares including at least one X class flare. The resulting CME’s have sparked displays of aurora over the last few days.

A parade of large sunspots crossing the disk of the Sun on 11 Aug 2024
A parade of large sunspots crossing the disk of the Sun on 11 Aug 2024

The equipment is capable of yet better images, but I would need better conditions than the poor seeing we usually get in Waikoloa. Perhaps load up the ‘scope and travel to higher ground.

A Busy Sun

Solar maximum is upon us and the Sun is a very busy place these days. To the delight of those of use who watch, a parade of large sunspots can be observed crossing the Earth facing side. These magnetic tangles have also been releasing flare after flare, sometimes causing strong araoras here on Earth.

It is cetianly worth the effort to drag the ‘scope into the driveway and take a look. Unfortunately the seeing at the house was poor this morning so the resulting photos are not as sharp as I would like…

A parade of large sunspots crossing the disk of the Sun on 10 Aug 2024.
A parade of large sunspots crossing the disk of the Sun on 10 Aug 2024.

LED Microscope Lights

I have owned this stereo microscope since I was a teenager. At first used for examining rocks and minerals in my collection, it has found many uses over the years, mostly used during assembly and inspection of various bits of electronic gear. It has been a workhorse microscope, well used, and well loved.

An American Optical model 40 stereo microscope
An American Optical model 40 stereo microscope

Despite this it bit me!

I know the feeling all too well, that little 60Hz nibble of 120Vac electrical power, a feeling anyone who has worked with electricity like I have recognizes instantly. Somewhere in this microscope 120Vac power is shorted to the frame.

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Welcome Interference

As I sit typing away I have a slight interferece to deal with. Rasalhague is sleeping just above my keyboard.

Rasalhague dreams atop the compter desk
Rasalhague dreams atop the compter desk

He came for the scritching, then eventually fell asleep as I worked on a user manual.

Not much interference… Just push his tail under the monitor rather than in front of the screen. There is a soft paw to push out of the way if I need to type numerals at the top of the keyboard.

Ras is deep asleep, his paws twitching slightly as he wanders in an unknown dreamland. Chasing Geckoes about the house? Or running off the doves that frequent our lanai? I have only guesses.

Whatever his dreams I am sure it is more fun that configuration registers, control loop settings, and relay connections.

Out of Place

Around this island the observant hiker will become attuned to various clues that give a view into the natural history or human history of the landscape.

An ʻopihi shell found along a utility line access road far from the ocean
An ʻopihi shell found along a utility line access road far from the ocean

One such clue is the presence of seashells, these are usually a giveaway of ancient Hawaiian occupation of a site or locality. The bleached and broken bits of shell a long lasting remant of meals harvested from the shoreline and brought to places well inland. Often found around lava tubes or water sources these shells let you know that others have passed here before.

An ʻopihi shell along a power line access road near Waikoloa? This is a bit unexpected. I have to stop and pick up this shell, pausing my trek to puzzle out this anomaly.

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