30 votes

Why can't observatories just stop capturing for a few seconds when Starlink satellites pass though their field of view?

Tl;dr, From personal experience, it’s not worth it. It’s a lot easier to throw away bad data than to try to calculate when stop. There’s not a lot of ambiguity as to whether it messes up the data. As ...
Justin T's user avatar
  • 3,394
21 votes
Accepted

Will the Vera C. Rubin Observatory (formerly the LSST) make a significant increase in the rate of astronomical event alerts?

Yes. The estimates are that LSST will produce about 10 million alerts per night (LSST Alert Distribution presentation) which will be at least a factor of 5x greater than the amount coming from ZTF ...
astrosnapper's user avatar
  • 8,357
18 votes
Accepted

What did I photograph?

A contrast stretch reveals stars down to magnitude 4 or 5. The stars you asked about are Deneb (center) and Vega (bottom). The constellation in the center and below is Cygnus; we also see Cepheus at ...
Mike G's user avatar
  • 18.7k
17 votes

Why are there so many seemingly blue-shifted galaxies in deep space

You cannot gauge the redshift of a galaxy by looking at a false colour image. The images taken through different filters are stacked and colourised to suit. You can say that the blue galaxies are ...
ProfRob's user avatar
  • 152k
14 votes

Why aren't there any images of Sun-orbiting bodies by Spitzer?

All "big" instruments have observation logs, so does Spitzer. The complete logs are here but there's also a filtered log for solar system observations which shows basically all planets and ...
planetmaker's user avatar
  • 19.4k
12 votes
Accepted

Binoculars 10x50 in light polluted place

This is totally anecdotal, but based on my own observations with a pair of 10x50 binoculars on a light-polluted suburban street in South East England... Rings of Saturn: No Moons of Jupiter: Yes, all ...
JayFor's user avatar
  • 236
12 votes
Accepted

Does the existence of hydrogen in the universe create an obscuration effect similar to the way air does at great distances?

One way of thinking about this is in terms of the physics of the cosmic microwave background. The cosmic microwave background occurs as a phenomenon when a nearly homogeneous universe transitions ...
ProfRob's user avatar
  • 152k
11 votes

Power of the James Webb Space Telescope

It all comes down to the brightness of objects (not their size). For all intents and purposes we can assume that the most distant galaxies and the small, but much closer, objects in the Oort clouds ...
ProfRob's user avatar
  • 152k
10 votes
Accepted

What is the "lost light" in this unusual Hubble Deep Sky image?

Let me see if I can explain the main aim and accomplishment of this work. First off: the picture you're puzzling over is a "luminance RGB" image, in which the bright regions are represented by color (...
Peter Erwin's user avatar
  • 16.7k
9 votes

Gravitational mirroring: Can we theoretically see the Milky Way using a telescope?

In theory, it's possible, but in practice it's extremely unlikely. The deflection angle is small unless the light ray passes very close to the centre of mass of a compact lensing body. From Wikipedia, ...
PM 2Ring's user avatar
  • 14.5k
8 votes

What is the "lost light" in this unusual Hubble Deep Sky image?

When you plug the lead researcher's name into Arxiv, the first search result is The missing light of the Hubble Ultra Deep Field. 3 main steps: Creation of sky flat fields for the four filters....
Hobbes's user avatar
  • 3,034
8 votes
Accepted

Is it practical to build a giant telescope in Moon? (Considering the fact that the atmosphere of moon is very rare)

It's very unlikely that large optical telescopes will ever be built on the Moon, because the Moon is almost the worst possible place to build them. (The surfaces any of the planets other than Earth ...
Mark Olson's user avatar
  • 7,650
8 votes

Why aren't there any images of Sun-orbiting bodies by Spitzer?

In addition to the target list linked to by @planetmaker in their answer, there are two recently published review articles (from Nature Astronomy) summarizing the many different aspects of Solar ...
Peter Erwin's user avatar
  • 16.7k
7 votes

Why are there so many seemingly blue-shifted galaxies in deep space

There are two factors here. First, to construct an image such as this, several optical filters are used, and then these are then merged to give an image. The colours that you see are therefore not ...
James K's user avatar
  • 122k
7 votes

Will we ever be able to see the surface of exoplanets directly?

To see an exoplanet "directly" requires us to (i) be able to separate it from the contrast-destroying presence of the host star it is orbiting and (ii) to be able to spatially resolve the ...
ProfRob's user avatar
  • 152k
7 votes
Accepted

What can I see with different apertures?

In Observing Handbook and Catalogue of Deep-Sky Objects, Luginbuhl and Skiff describe how hundreds of deep-sky objects look in different apertures. For example, for galaxy M63 (NGC 5055) in Canes ...
Mike G's user avatar
  • 18.7k
6 votes
Accepted

What causes these asteroid trails to be so strangely shaped and repeated?

What causes these asteroid trails to be so strangely shaped and repeated? The linked image is a composite of several long duration exposures captured by the Hubble Advanced Camera for Surveys of the ...
David Hammen's user avatar
6 votes

Does the existence of hydrogen in the universe create an obscuration effect similar to the way air does at great distances?

In a sense yes - there is interstellar (i.e. intra-galactic) absorption of Lyman-$\alpha$ photons by neutral hydrogen. This plays a role e.g. when trying to determine how much hydrogen is lost from ...
AtmosphericPrisonEscape's user avatar
5 votes

When a rogue brown dwarf star hits a white dwarf star, will the collision at most cause a nova?

Collisions between a rogue brown dwarf and any other star would be very rare because the space between them is so vast. I don't want to say it'd never happen, but it would be a rare event. It's ...
userLTK's user avatar
  • 24k
5 votes
Accepted

What have we learned from the observation of most distant galaxies

Nearby galaxies are seen in their old age. Distant galaxies are, on average, the same age as the local ones. But due to the finite speed of light, the farther you look, the younger you observe them. ...
pela's user avatar
  • 38.3k
5 votes

Optical Observation Calls: How and Where to apply for optical observations?

Optical observatories -- or commissions that allocate time on a national or international basis to one or more telescopes -- generally accept proposals twice a year, during a one-month period with a ...
Peter Erwin's user avatar
  • 16.7k
5 votes

Narrowband imaging wavelengths in NIR?

The main problem with NIR is that the atmosphere quickly becomes opaque for various bands inside the range due to the absorption bands of water vapour. E.g. see a lecture document on spectral ...
planetmaker's user avatar
  • 19.4k
5 votes
Accepted

Narrowband imaging wavelengths in NIR?

Yes, there are some obvious nebular emission lines in this range - the whole of the Paschen series (transitions in hydrogen atoms to the $n=3$ level) lie between Paschen alpha at 1875 nm to the ...
ProfRob's user avatar
  • 152k
4 votes

What is the largest (angular) dark area in the sky?

Barnard 68 is the first thing that comes to mind for me, it is a little over 10' across and is opaque in the visible spectrum. I'm sure there could be something much larger out there, but like I ...
LaserYeti's user avatar
  • 736
4 votes

How to locate nebulas visible through AstroMaster 114 telescope without device assistance?

Those targets are good choices for beginners at the right times of year. However, in June M42 is a daytime object, and M31 rises in the wee hours, leaving only M13 and Albireo in the evening. Other ...
Mike G's user avatar
  • 18.7k
4 votes
Accepted

Cases of gravitational lensing resulting in a recognizable image of an extended object?

There are actually quite a few examples of this. A particularly nice one, where you can see star-forming substructure within the distant, lensed galaxy (the extended, vertical "snake" structure just ...
Peter Erwin's user avatar
  • 16.7k
4 votes

Will we ever be able to see the surface of exoplanets directly?

This kind of question is a bit speculative since we can't predict the future. But humanity has come up with many ways to do something that seemed impossible in the past, as @PierrePaquette said. ...
User123's user avatar
  • 2,879
3 votes

What did I photograph?

At the f-number you have used, you'd already expect to get weird images. In astronomy we usually use $f=\infty$, but this is of course only relevant for extended objects, not point like sources. But ...
AtmosphericPrisonEscape's user avatar

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