Photography

2022-06-04

M13 and M13

M13 and a distant galaxy, NGC6207. Slightly cropped.

There’s a delicate hint of pink in the middle of the cluster — it is probably necessary to expand the picture to the max to see it. The pink is undoubtedly an artifact. (However, Wikipedia states that the brightest star in the cluster is a red giant… Could it be the color comes from that star??? Nah.)

The tiny galaxy to the Northeast (by accident, the orientation is roughly correct), NGC6207, is quite pretty when seen by the Hubble.

I process images using PixInsight, plus GIMP for the final touch-up. The most important single step in the process is called “stretching” — even with long exposures, an unprocessed image is dim to the point of being almost black. Something like:

unstretched image of M13 — Unstretched image of M13

If you maximize the image and look very closely, you will see a few stars (I count 15) and, in the middle, a faint ghost of M13. (I cheated — this image has actually been stretched slightly — otherwise, there wouldn’t even be a ghost!)

Though big telescopes are fabulously expensive and finicky to set up, the computing power necessary for image processing is readily available to the common nerd like me. And a telescope is not required — for example, the enormous trove of Raw Hubble Data is available online, for free.

2022-05-26

The Whale and the Crowbar (or Hockey Stick)

Another try. Slightly better processing and a dozen more five-minute exposures added. The tiny fuzzy ball above the whale is a companion dwarf elliptical galaxy, NGC4627. All three galaxies are about the same distance from us, and they interact. Hence the odd shapes.

2022-05-22

Iris Nebula, NGC7023

Reprocessed with yet more data. I don’t know that this is significantly better than my previous results ( here and here and here ). But NGC7023 is a fascinating object, and I will probably return to it for the rest of my life. As always, the images available from Wikipedia are worth a pause.

2022-05-21

IC2574

IC2574 is the faint smudge in the center, 13 million light-years away. A dim dwarf spiral galaxy. According to Wikipedia, approximately 90% of its mass is dark matter.

Taken with a 110mm F/7 refractor. Total exposure time is about 13 hours.

2022-05-202022-05-20

M63

Sometimes referred to as “the Sunflower Galaxy”. This image has about 7 hours total exposure time. It is quite a pretty galaxy — if you zoom in (ie, click on the picture), it looks like a swirl of altocumulus clouds on a spring day.

2022-05-07

Fountain in Seville

Accidents happen. The stop in Seville was less than ideal: dock in Cadiz, catch an early morning bus, then a walking tour of a couple of high points of Seville. Back to the bus, back to the ship. I don’t remember taking this picture, but there are many other images of the area on my camera, so I must have. Anyway, I thought it was nice:

It’s a color image, though it looks B&W.

2022-04-09

M97 and M108

M97 is also known as “the Owl Nebula” — you can barely see the two eyes. M108 is known, for some reason, as the “Surfboard Galaxy”. North, by the way, is to the right.

M108 is also the galaxy on the left edge of the images I posted yesterday. The image yesterday was a failed attempt to integrate 14 separate exposures; the image above was a successful attempt to integrate 16 (different) exposures. Yesterday’s failure haunts me — I worked on it for hours. Here’s a cut from the above image of approximately the same aspect:

Striking, to me at least, is that there were two stars in this region in yesterday’s image, but only one here. I’m pretty sure that this image is a better reflection of reality… Perhaps that is a clue about what I was doing wrong!

2022-04-082022-05-03

S/N

A colorful mosaic; an extreme magnification of an image of space at the edge of a galaxy. Two prominent stars, some bright spots that are probably just defects in the sensor, or maybe where a cosmic ray hit and produced a single bright flash. Mostly, this is just visual noise.

Here’s a different version, where the individual pixels have been smoothed:

A prettified instantaneous snapshot of the quantum noise roiling across the sensor. Perhaps if I could make a movie, these would be tiny agitated multicolored ripples. But the two stars would remain, hard reminders of a real world, and the brightness at the right edge would also remain, testifying to that galaxy — M108, I’ve heard — off-screen to the right.

Edit: I’ve since discovered that one of those stars must be an image-processing artifact. So much for reality.

2022-04-02

NGC4244

Another galaxy floating in splendid isolation. According to this Wikipedia article it is part of the M94 group, which is loosely bound to the extent that some members are just “moving with the expansion of the universe”.

Take that, Putin!

2022-04-01

Tadpole Nebula

The “tadpoles” are slightly lower left of center. There are two of them: bright structures rather than the usual dark spots.