The Observatory

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4:31 AM

Q: How bright is the Crab Pulsar's 30 Hz modulation in visible light? What color is it?

This answer to Has great eyesight been necessary for astronomers? mentions Astronomer Jocelyn Bell Burnell's recounting of a likely first visual observation of a pulsar. This can be found for example in Nature's Air force had early warning of pulsars The work preceded by several months the ob...

Gee, I'm jealous! Maybe it is about time I get back into amateur observing and get a telescope. I have some friends with a nice flat roof on their house who enjoy occasional observing, but it's near Taipei and close to sea level. So I need something portable.

For fun and wow! and portability (and not astrophotography), perhaps Dobsonian is the way to go? I could make it a fun project; buy a mirror, diagonal and eyepiece holder and DIY the rest?

It seems the Crab Nebular pulsar is +16.5 magnitude and pulsing at 30 Hz, per the story in the question above, you might be able to detect it visually, though if it's dim, perhaps not.

Also:

Q: Who first reported the Crab pulsar's pulsing but was dismissed by an astronomer?

discoveries astronomy

@Slate speaking of eyepiece specifications, any thoughts on:

Q: How does eyepiece exit pupil diameter affect image clarity and viewing experience?

This answer to Not Able to View Objects with Barlow Lens includes a calculation of exit pupil diameter as a way to address the limits of useful magnification when observing planets with a small telescope. A comment there cites Sky & Telescope's Stargazer's Corner: Adventures Under the Night Sky's...

telescope amateur-observing optics binoculars eyepiece

2 hours later…

Slate

7:05 AM

@uhoh I know there are a number of folks who actually make their own mirrors, too, though as far as I know it's a decent amount of work. I guess it all depends on what you're going for, and what your budget is! And, tbh, how portable you need it to be. The best telescope is the one you'll use ;)

Not quite sure the crab pulsar would be visible, I might need a fair bit more aperture to see it. It's also a bit early in the year for it, I think, judging by its position in Stellarium. That said, I'll earmark it and give it a shot in the coming months...

Unfortunately I don't think I have enough firsthand experience to help with that question. I could take a guess, or aggregate information based on what I've read, but I'm not sure my own knowledge would be informative enough to write up. (At least for now.)

I'm still pretty new to the hobby overall.

2 hours later…

uhoh

9:37 AM

Making the mirror is certainly a "rite of passage" I've dreamed of for a half-century, but I don't think I can manage the workspace and the time at this point. If I'm going to go Dobsonian then the question is if it's in the end actually cheaper to buy a used one than to try to build everything from scratch.

I guess I'll start poking around in old Sky & Telescopes for bottom of the barrel DIY Dobsonian mount projects and look around at the (likely very small) used telescope market here.

5 hours later…

Slate

3:04 PM

I think it's cheaper to buy a used one?

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