Jason Nishiyama @evilscientistca@octodon.social
Teacher, astronomer, political scientist and father.
The planet Uranus was originally called Georgium Sidus (George's Star) by its discoverer William Herschel. This didn't go well outside of Britain so it was named after the Greek deity of the sky. English speaking astronomers have had to deal with the giggling ever since.
M57 - the Ring Nebula - is a planetary nebula in the constellation Lyra. A dying star that has ejected its outer layers, kinematic studies of M57 suggest that it is actually barrel shaped and that we are looking down one end.
Henrietta Swan Leavitt discovered the Cepheid variable period-luminosity relationship. This relationship links the absolute brightness of a Cepheid type variable star to its pulsation period. This gave us an important standard candle to measure distances across space.
Squeeee!
In the 1920s Edwin Hubble used his discovery of Cepheid variable stars in both M31 and M33 to work out the distance to these two galaxies. This showed that the then called "spiral nebulae" were actually galaxies outside of our own - making our universe much larger.
Seeing is caused by the moving of our atmosphere. It causes stars to twinkle and causes images to be blurry. It can be seen in this movie of Saturn. Good seeing has less motion. Hubble avoids this problem by being in space.
M51 is an interacting galaxy in Canes Venatici. It is located just off the furthest handle star in the Big Dipper. It is about 24 Mly away.
Most of the things on Charles Messier's eponymous list look fuzzy through a small telescope and hence could be mistaken for a comet, which Messier was trying to find. So M40, the only double star on the list, is a bit of a puzzle as to why he added it.
This is how NASA writes software:
https://www.fastcompany.com/28121/they-write-right-stuff
I want the software driving cars around my family to be held to the a similar standard of quality. In the context of self-driving cars, "Move fast and break things" means "Half-arse it and kill people."
Humans in the USA manage 1.16 fatalities per 100,000,000 miles travelled. Uber's software couldn't even get to 3 million miles before it killed someone.
We do this properly, or not at all.
This shot of M101 is from the @RAOastronomy Baker-Nunn telescope. M101 is visible below centre. The arrows point to other galaxies that I was able to identify in the image.
Spectroscopy tells us many things including what things are made of. The dark lines in this spectrum of Aldebaran are made by the various elements in it. Each element has a unique set of lines which identifies it.
A society that places things (firearms, low taxes, convenience over safety, religious dogma, etc.) above its children is lost.
Another frustrating night of guidance problems...
NGC 6826 is known as the blinking planetary as its brightness is such that in a small telescope it seems to disappear or blink when you look directly at it. It's about 5000 ly distant.
A focusing mask is often used in astrophotography to ensure a sharp focus. With this mask, when a line appears in the middle of the created image, the telescope is focused.
Artificial satellites are a bit of a hazard when imaging the sky. This one went right through the target, making the image useless.
The space between stars in galaxies is so great that when galaxies collide there are hardly any collisions if any at all between stars.
This is what happens when the autoguide system goes haywire during a 10 minute exposure on a telescope...
From Saturday - the Galaxies M66 (L) and M65 (R) in the constellation Leo. 0.2m telescope. 5 min L, 2 min each RGB.
M66 is ~31 Mly from Earth, M65 is ~40 Mly away.
