Questions tagged [observational-astronomy]

Questions about the techniques and practice of observing the night sky.

Filter by
Sorted by
Tagged with
0
votes
0answers
70 views

Difference in astrophysics and astronomy phd [closed]

Upon looking at the department of physics for a university I want to attend , I found that they only offer a bachelors degree in astrophysics but a phd in astronomy. Would the phd in astronomy include ...
6
votes
3answers
2k views

Could someone explain what is wrong with my telescope, and what should I be able to see with it?

In January of 2016, I received my first telescope, through Astronomers Without Borders. It was and is my first telescope: an AWB 130 Newtonian tabletop telescope with a 650mm focal length and a 130mm ...
-5
votes
0answers
35 views

How many bright IR sources would you expect to see in a young gas cloud? [closed]

During the 10 million years of star formation in a gas cloud, a typical star spends 2 million years of its life as an IR bright protostar. At any particular moment, How many bright IR sources would ...
0
votes
0answers
60 views

If the ratio of actual total mass to critical mass (Ω) in the universe is only about 0.3, why do cosmologists believe it is flat, as far as we see?

What about astronomical observations makes scientists believe our universe is flat, at least as far as they can tell? Despite the critical Friedmann density being less than one, plus the existence of ...
3
votes
1answer
232 views

How old is the idea of the far side of the Moon?

The far side of the Moon is the side which always faces away from the Earth, due to tidal locking. Due to libration, about 18% of this far side can be seen at one point or another through telescopes. ...
20
votes
4answers
4k views

Where is it possible to observe the Moon for 24 hours?

I wrote an astronomy olympiad yesterday and there was one task I couldn't figure out an answer to: Estimate at what latitudes it is possible to observe the Moon for at least 24 hours. Under what ...
1
vote
0answers
21 views

Find Periodicity in Lightcurve Using Lombscargle Periodogram(Astropy)

How to find the Nyquist factor for unevenly sampled data like here.https://github.com/jakevdp/PracticalLombScargle/blob/master/figures/LINEAR_Example.ipynb ? I have time binned for 5 mins. I mean for ...
5
votes
1answer
629 views

Why are type 1b and type 1c supernovae called type 1 rather than type 2; if they result from large exploding stars, rather than accreting dwarfs?

What similarities do types Ib and Ic supernovae have in common with type 1a? Are their spectra or their magnitudes more similar to accreting white dwarfs than the other supermassive, main sequence, ...
1
vote
0answers
34 views

Can we measure planetary Love number of exoplanets?

I understand that Love number is the ratio between the tide raising potential to the actual deformation of the body, however, I'm not sure if there are ways to detect the Love number from observations ...
15
votes
2answers
2k views

Are there any gaps in the range of gravitational wave frequencies we can detect?

We have LIGO and other earth-based interferometers for detecting high-frequency gravitational waves, we're going to have satellites in orbit around the sun for low-frequency waves, and we have a ...
6
votes
1answer
189 views

Can stars really be seen after sunrise from Mount Everest?

I came across this image taken on the "Balcony" at over 27,000 ft (8,200 m) elevation, beneath the summit of Mount Everest. So many stars can be seen on it even though the Sun has risen. Do ...
1
vote
0answers
54 views

Could we optically observe metallic hydrogen in space?

As many calculations have been done on whether metallic hydrogen is metastable or not in low-pressure environment, It occurred to me that by the fact that we have not observed any metallic hydrogen so ...
1
vote
0answers
46 views

How can I recognize the stars in a .fit image and get information about their magnitude and intensity?

I have an image (.fit file) in which there is a satellite (streak) and a stellar field. I have extrapolated the intensity of the centroid of the streak (in gray scale) and I have assumed this ...
1
vote
0answers
42 views

Using AstroImageJ to find apparent magnitude of a satellite

I have a set of 30 images in .fit format. I would like to use AstroImageJ and find for each frame the apparent magnitude of the satellite (the streak in the figure). I have found a similar question in ...
1
vote
1answer
38 views

What is a photoelectric scanner?

I am reading this article by Wing, Peimbert and Spinrad, where they mention the use of a photoelectric scanner. By searching online, I find that photoelectric scanners are used to scan punchcards, ...
1
vote
0answers
90 views

Converting equatorial coordinates (RA, DEC) in pixel coordinates (.fit file)

I have a .fit file that gives me the coordinates (right ascension and declination as you can see in the image of the Header file)of the satellite; the satellite is circled in green in the second image....
0
votes
0answers
46 views

Weird object seen moving through space binoculars (irregular pattern) [duplicate]

I was looking up to the western sky with some very high powered binoculars. I am just grooming the sky looking at things I cannot see with my naked eye. I then run into this box like constellation ...
1
vote
1answer
46 views

Why would radio astronomers choose ¹³CO and C¹⁸O spectral lines instead of the most isotopically common combination?

Wikipedia's T Tauri explains that this system is an atypical example of T Tauri stars. It says: As typical for the young stars, all three stars of T Tauri system are surrounded by a compact disks ...
12
votes
2answers
2k views

How do we know that objects that appear in duplicate or triplicate, etc. due to strong gravitational lensing aren't actually multiple objects?

If we are looking at faraway objects, there is no parallax view, correct? So isn't there a chance that an object that appears multiple due to strong foreground gravitational lensing is actually ...
10
votes
2answers
2k views

How big would a telescope have to be to get a good look at the nearest neutron star?

It's my understanding of observational astronomy that the size of a telescope limits its effective angular resolution, which is why scientists needed to use radio telescopes all over the globe to look ...
1
vote
0answers
14 views

How does one think about optical depth in the context of gravitational microlensing? Is it measured or deduced from observations? Used for planning?

This excellent answer to Which studies prior to 2018 "claimed to find evidence of extragalactic planets in the Andromeda galaxy"? Which instrument was used? introduces the technique of "...
2
votes
1answer
91 views
+100

Have interference effects (in space) ever been observed by a single instrument, as opposed to interferometry?

Not asking about: Interferometry can be done with multiple instruments who's light paths or signals are combined interferometrically, or even between different parts of a single aperture, e.g. What ...
1
vote
3answers
57 views

Looking for an interactive star chart

First, apologies; I understand this is like a software request over at Stack Overflow. I'm looking for a star chart for a friend that likes to stargaze while in his outdoors hot tub. He is at latitude ...
0
votes
1answer
80 views

When will Alpha Centauri A and B overtake Proxima Centauri as the closest stars to us?

There are 3 stars in the Alpha Centauri system: 2 large stars orbting around each other (A & B) and a distant Proxima Centauri (C) orbiting around both. Right now it just happens that Proxima ...
1
vote
1answer
45 views

Which studies prior to 2018 "claimed to find evidence of extragalactic planets in the Andromeda galaxy"? Which instrument was used?

After the first round of popular news items about the "first extragalactic exoplanet" discovery, CNET's Did astronomers find the first planet outside of the Milky Way? It's complicated ...
1
vote
0answers
28 views

Which University of Oklahoma research purported to "detect thousands of extragalactic planets back in 2018"? Which instrument was used?

After the first round of popular news items about the "first extragalactic exoplanet" discovery, CNET's Did astronomers find the first planet outside of the Milky Way? It's complicated ...
5
votes
2answers
55 views

After only one eclipse of its X-ray bright primary, how can astronomers estimate the first extragalactic exoplanet's period to be about 70 years?

Phys.org's Astronomers may have discovered the first planet outside of our galaxy says: While this is a tantalizing study, more data would be needed to verify the interpretation as an extragalactic ...
3
votes
0answers
35 views

Is the Arid meteor shower the first to be discovered photographically?

@planetmaker's answer to How can Mercury's sodium tail be imaged? links to Ciel et Espace (Sky and Space) and browsing through I found this tantalizing beginning of an article (reading the rest ...
1
vote
0answers
25 views

balmer alpha , beta line intensity [closed]

In different temperature environments, the intensity of the Balmer lines is determined by the Saha equation and the Boltzmann equation. What I'm curious about is as follows. How can we measure the ...
-4
votes
2answers
132 views

Telescope/s functioning from underground mines

Theoretically and Practically, Can a Telescope function for the astronomer observed from underground mines? By "telescope" I mean the instrument used by astronomers to observe stars, planets ...
2
votes
2answers
132 views

By type, how far out do we have good star maps?

First off, these questions asked by others seem related, but each asks a slightly different question and neither have very good answers: How well have we mapped our local neighborhood of stars? ...
-1
votes
1answer
50 views

What is the 'AT' astronomical catalogue? And the 'TXS' one? As in AT2019dsg and AT2019fdr?

I cannot find a site stating what the AT or TXS star/astronomy catalogues are, even though some AT and TXS 'events' have been in the news lately....
0
votes
1answer
28 views

What is Hubbles WFC3 "UVIS 47 G200" filter? What is it used for? How to find an example?

Extensive reading for Are the dispersion directions of the prism and the grating in Hubble WFC3 UVIS G280 perpendicular? Can we call this a "grism"? With cross-disparsion? led me to ...
2
votes
1answer
61 views

Are the dispersion directions of the prism and the grating in Hubble WFC3 UVIS G280 perpendicular? Can we call this a "grism"? With cross-disparsion?

Prologue From Into the UV: A precise transmission spectrum of HAT-P-41b using Hubble's WFC3/UVIS G280 grism: The UVIS grism, however, comes with several quirks that make it difficult to observe with ...
4
votes
0answers
76 views

Sudden spikes on the light curve of a Quasar from K2 mission

I obtained the optical light curve of 3C 273 QSO from the MAST repository off the K2 mission and plotted it by making the FITS into a CSV file through Pandas dataframe and plotting the obtained ...
3
votes
2answers
78 views

Which Venus scientists discovered the hole in the ozone layer?

After 21:00 in Venus: Earth’s Evil Twin or Just Misunderstood? (live public talk) from the JPL YouTube channel the person being interviewed "Sue Smrekar, Rocky ...
3
votes
1answer
95 views

Why is the Nancy Grace Roman Space Telescope's field of view shaped like a PacMan "ghost"?

The Curious Droid YouTube video NASA's Mega Hubble - The Roman Space Telescope illustrates the shape of the telescope's field of view and the outline has a smile or frown shape. For whatever reason it ...
2
votes
0answers
42 views

Farthest observed protoplanetary disk observed at radio frequencies? Catalog

This could be a naive question or maybe too easy to solve (I do not really know!). Brief context: I'm interested in a certain planetary system at $d \sim 300 \, \mathrm{pc}$. It would be really nice ...
6
votes
1answer
64 views

Why Nyquist Sampling Rate depends on Bandwidth and not max frequency?

Is the Nyquist sampling rate same for different bands if those bands have same bandwith? E.g. Would the Nyquist Sampling rate be same for 1000-1400 MHz band as for 100-500 MHz band because both the ...
3
votes
1answer
57 views

Shortest and longest wavelengths at which exoplanets have been resolved from their primaries?

Phys.org's Radio signals from distant stars suggest hidden planets summarizes the Nature Astronomy paper The population of M dwarfs observed at low radio frequencies (also in arXiv) but this is an ...
2
votes
1answer
44 views

Obtaining the Flux-Time plot for a Quasar

As a follow up question to Obtaining the Light curve of a a Quasar, I wish to know how to obtain a Light curve for a quasar observation like this data set over here. Is there an archival repository ...
5
votes
0answers
74 views

rms noise, confusion and dynamic range in radio images

I have been trying to understand imaging in radio astronomy. Below are some of my questions related to it and my understanding of their answers. I am not very confident about my understanding of them ...
6
votes
0answers
117 views

How exactly was Giovanni Cassini able to measure the distance to Mars?

Recently learned that Cassini was able to calculate the distance to Mars quite well using parallax in 1671. I was surprised, since even at opposition of Mars, the parallax (with respect to the Earth's ...
4
votes
1answer
285 views

Why was there a gap in exoplanet detection in 2015?

The question How has the number of known TNOs evolved over time? contains a link to this image: Number of extrasolar planet discoveries per year through April 2018, with colors indicating method of ...
5
votes
2answers
175 views

Can Mercury be seen from the 60th parallel north on Earth? Shetland, Faroe, Norway, St Petersburg, Alaska

I'm originally from a city in Spain which is 40 degrees north, and I used to watch Mercury (naked eye and telescope) every time I had the opportunity, that is, when Mercury was at maximum elongation ...
0
votes
0answers
26 views

How exactly does NEOSTEL's fly's eye telescope's secondary mirror array split the primary beam among sixteen cameras?

Wikipedia's NEOSTEL says: The Near Earth Object Survey TELescope (NEOSTEL - also known as "Flyeye") is an astronomical survey and early-warning system for detecting near-Earth objects sized ...
4
votes
0answers
48 views

How does the Hubble Space Telescope measure the speed of the wind inside Jupiter's Great Red Spot?

Space.com's Jupiter's winds of change show increased storm speeds in Great Red Spot and Hubblesite.org's Hubble Shows Winds in Jupiter's Great Red Spot are Speeding Up both link to the recent open ...
2
votes
1answer
58 views

Query Gaia by star name

I am attempting to query Gaia programmatically in python to get certain properties for specific stars. I can write a query which obtains some properties, but only for all stars, not a set of stars or ...
1
vote
0answers
19 views

How to calculate S/N in galaxy absorption spectra?

I want to calculate the S/N of an galaxy absorption spectrum. I therefore chose a part of the spectrum which contains very little to none absorption features and should be only made up of noise and ...
5
votes
1answer
328 views

How was the recently publicized Hubble image of a distant galaxy showing clearly resolved lensed in an Einstein ring produced? When was it produced?

The 24-Sep-2021 NASA Goddard video Einstein Ring Spotted by Hubble and it's Goddard Media Studio's page Einstein Ring Spotted By Hubble discuss the image, but don't really give credit to how it was ...

1
2 3 4 5
20