Latest posts
- Making cooled clothing:Jul 12, 2026
Summer gets really hot, and it's not going to get better anytime soon. At my place, it isn't actively dangerous yet, but it's still unpleasant. A normal air conditioner uses a low boiling-point liquid: something like liquid propane can boil down to -42 C. Just like water, it's evaporation absorbs a lot of heat and the remaining liquid will become very cold. Of course, releasing the gas would
- The Tadpole galaxy:Jul 09, 2026
North is up (exact, mirrored). 0.53 "/pixel [18.8' x 7.4'] FWHM = 4.2" This galaxy has a massive (and rather bright) tidal tail, but I can't see an obvious companion galaxy. The general consensus is that there's a second galaxy behind it... although a nearby elliptical has a suspiciously similar redshift: Total exposure time:364 * 30 seconds = 3 hours. Used in stack:165 * 30 seconds = 1
- Arp 90Jul 08, 2026
North is up (mirrored, exact). 0.53"/px [15' x 9.2' field]. FWHM = 3.9" Arp 90 is the two interacting galaxies in the east. Total exposure time:314 * 30 seconds = 2.6 hours. Used in stack:276 * 30 seconds = 2.3 hours. Telescope: C9.25 (230mm, f/10, fl=2300mm) + 0.63 Starizona reducer Camera: IMX533 (16mm diagonal, square, color) Processing: Callibration (dark + flat) Stacking (average w/
- Stephan's QuintetJul 06, 2026
North is right (mirrored). 0.53"/pixel [17'x12' field]. FWHM=3.7" Ok, this is a crazy one. Five tightly spaced galaxies with visible tidal interactions: However, looking at redshift data, the blue spiral on the left is ten times closer than all the other objects: at z=0.0026 instead of z=0.022. This means it's not actually a member of the group, even though it's in the same part of of the sky
- Arp 38: not that peculiarJun 27, 2026
Data is from 2026-06-20. North is right. 0.53"/pixel (27'x27' field). FWHM=4' A nice, if rather small (~100") edge on spiral galaxy. Arp filed this one under "low surface brightness companions", but the companion doesn't seem to exist. There's a bright spot to the north (right) of the core, but hubble data shows it's just a bright HII region and star cluster. This part of the sky isn't cover