New answers tagged

1

On the fast radio burst side of things: The FRB distribution is isotropic so far, which isn't surprising - you'd expect cosmological sources of this sort to be more or less everywhere in the sky. This means that you could point your telescope at random and still have a roughly equal chance of detecting one - albeit an extremely low chance. Fortunately, in ...


2

You are using the webcam as an electronic eyepiece. People have been using various types of cameras as eyepiece for decades. The reason for the small field of view is the small (1/4") sensor of the camera. Only a part of the actual field of view strikes the sensor. The field of view of your telescope will likely cover a 2" eyepiece. You are putting ...


7

I found an openly available CZ-5B Rocket Body (ID 48275) reentry prediction: Most intersting I found the following graph which shows how slowly error bars of the predicted reentry time decrease over time (as obtained from The Aerospace Corporation Tweet): Last but not least, I also learned from a Business Insider story called "The US is tracking an ...


8

The name of the module is Tianhe (天和), and the name of the rocket is Long March 5B, but it got a special designation of 2021-035B. It is not really official, but I think it is good enough to get some data. I found this website for current position (live on globe). Your userpage says you live in Europe, so the rocket will fly over Greece at 00:30 CEST (22:30 ...


20

This is because your image is not in focus. So you’re seeing the shadow of the secondary mirror. You should have a knob near the eyepiece, that you can turn to adjust focus. You need to turn it, one way or another, until the image is as small as possible and as bright as possible. Good luck!


18

This is a heavily de-focused image (possibly taken through cloud looking at the orangeish "glow" to the right). The dark center of the "donut" is the shadow of the secondary mirror centered within the image/pupil coming from the primary mirror. The focus needs to be adjusted until the "donut" shrinks down to sharper points of ...


1

One way of thinking about this is to think of what, for instance, a digital sensor would see (does see!) when looking at a galaxy. Even if there is no dust to scatter light (which often there is), if there is, in most cases, one or more (generally 'more') stars in the bit of the image covered by a pixel in the sensor, then that pixel will be at least partly ...


4

You are mostly empty space. Every atom in your body is very tiny compared to the relatively vast spaces between it and its nearest neighbors. And the same goes for every "solid" object you ever saw. But when you look at yourself in a mirror, the number of atoms you see is so incredibly vast that you don't see the spaces between them but instead ...


-1

Don't trust your eyes when they tell you something is solid. Please remember that the stars are suns. So, if our galaxy were really solid, you'd directly look into a star's surface in every spot of the Milky Way, and that would mean a band in the sky where every spot shines as brightly as the sun. Then the Milky Way would be 100 times brighter than our sun's ...


1

The actual transparency of something depends on whether a light ray will pass through the object or hit something, becoming absorbed or scattered. The total cross-sectional area of the stars of a galaxy is microscopic. This is why one can see the background galaxy through the foreground galaxy in NGC3314: However, dust can be actually opaque in this sense. ...


-1

First, you are correct that galaxies are mostly empty space, at least in terms of stars. The Milky Way may have as many as 400 billion stars while Andromeda has roughly two and a half times that number. For the Milky Way that comes out to roughly one star every four light years, on average. Viewed from a distance, however, those stars are extremely bright ...


11

The cosmic horseshoe is beyond amateur instruments. It is a magnitude 20 object. In a large (2.5 m) professional telescope it looks like: This image taken from the SDSS III data. It is small (10'', half the size of Mars at opposition) but that is not insurmountable for amateur equipment. But is it very dim. If an object like this was visible in moderate ...


1

Partial answer to Is it possible i.e. with Python or other (I am only basic with soft)? Yes! Use Skyfield. As long as you can muster a little Python you can search for events, make topographical maps of event times and elevations, or even put it in a loop and find optimized locations. The nice thing about learning to use Skyfield is that you can then do ...


7

tl;dr No, not from Earth. Because of the ionosphere. Whistlers are VLF (very low frequency) hundreds to thousands of Hertz. Our ionosphere blocks electromagnetic radiation very reliably below say roughly 10 MHz depending on time of day and solar activity because it's a plasma. The image below shows peak whistler emissions at about 1 kHz. You can imagine that ...


10

Radio astronomy involves a wide range of frequencies, covering the range from $\sim$10 MHZ to $\sim$100 GHz.$^{\dagger}$ With four orders of magnitude to work with, the most valuable band depends strongly on what sort of object you're observing, as well as what receivers are actually available on a specific telescope. Given the diversity of sources out there,...


Top 50 recent answers are included