Jason Nishiyama @evilscientistca@octodon.social

Speaking of things that happened a lifetime ago... <picture of me a long time ago>

Often satellites will track through a telescope's FOV while imaging. This one took it's time taking three 1 min frames to cross. The FOV is 19.3 arcmin in x. Leftmost image is a combination of the other three. Advanced readers can use these to work out the orbit of the satellite.

M51 is a galaxy in Canes Venatici, though it's easily found just off the last star in the handle of the Big Dipper. It is a grand design spiral that is interacting with a nearby smaller galaxy. #astrophoto

New Raspberry Pi zero W. Step 1: install emacs...

Open star clusters, such as M36 shown here, are stars that formed together relatively recently and having left their nebular birthplace are now drifting slowly apart. Our Sun would have been part of such a cluster billions of years ago.

My photoshop-fu isn't the best but this 3 image moziac shows the relative positioning of the Flame Nebula and the Horsehead Nebula. #astrophoto

From Saturday night, The Horsehead Nebula. 0.2m f3.9 telescope. 10 minutes L, 5 minutes each R, G, and B. #astrophoto

They got the library at Alexandria, they're not getting mine...

Also from last night. NGC2024 - the Flame Nebula. 0.2m f3.9 telescope. 7 minutes L, 1 minute each R, G, and B. The very bright star at lower right is Alnitak, the leftmost star in Orion's belt. #astrophoto

From last night: spiral galaxy M77 in Cetus. It is about 52 million light years distant. 0.2m f3.9 Newtonian telescope. 9 minutes L, 5 minutes each R, G, and B. #astrophoto

‪Not quite clear enough for science imaging so telescope play time. ‬

Nebulae are great clouds of gas and dust in space. The mark both the births (left, M16) and deaths (centre M76, right M1) of stars.

The 24 hour day is only an average, known as mean solar time. Earth's elliptical orbit causes Earth to speed up and slow down so the time from noon to noon isn't constant. The equation of time (shown) gives the difference between the actual solar time and the mean solar time.

The solar day (noon till noon) is 24 hours long. This is about 4 minutes longer than the sidereal day (time for the Earth to rotate once on its axis). As Earth moves in it's orbit it has to rotate a little further for the Sun to be overhead again to compensate for the motion.

Our star the Sun is a middle aged star about halfway through its life. We've got about 5 billion years left in it, though as it slowly climbs across the main sequence of the HR diagram it will get hotter and the Earth will be uninhabitable in only a couple of billion years time.

Also from the science data, Planetary nebula NGC 2346. In this case used a low stretch H alpha image as the luminance channel to provide detail in the image. Look close and you can see the central star. 30 minutes each L (H alpha), R, G, and B. #astrophoto

From the science data, NGC650/M76 - the Little Dumbbell Nebula. Playing around in Photoshop to make a HDR image (left) out of a low and a high stretch image (centre and right) to show detail and faint areas. 30 minutes each R, G, and B. #astrophoto

The photometry is now done. Now it's just taking the magnitudes, doing some math and sulfur abundances are calculated for the two targets. Two more data points!

Stars selected and coordinates set. Target coordinates determined. Time to finally do some photometry!

With the observatory and airmass data now in all the images. Time to select some comparison stars. These have to be bright enough to be seen in the [SII] images, but not so bright they saturate out in the wide band filter images.