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Results tagged with observational-astronomy
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user 37191
Questions about the techniques and practice of observing the night sky.
2
votes
Can I find exoplanets without a telescope?
No. With a probability nearly equal 1 you will not find any exoplanet with naked eye from Earth, even under perfect conditions like no light-pollution. The human eye simply does not have enough resolu …
- 5,657
1
vote
How does the Helioseismic and Magnetic Imager (HMI) compute the Magnetic Activity Index (MAI)?
I found a quote from K. Jain et al. which defines a Magnetic Activity Index might be pointing you in the correct direction - for me it still sounds rather abstract:
To obtain the MAI, we convert mag …
- 5,657
3
votes
1
answer
99
views
Lightest object so far to function as gravitational lense?
Many amazing discovers are based on gravitational lensing and microlensing, but as non-expert it is not obvious to me:
What is the (current) lower mass limit of the lensing object(s) for which astrono …
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1
vote
1
answer
214
views
Observatories with public access in Europe
This is a follow-up to Observatories that allow public access with a smaller (geographical) scope.
I am interested in getting to know observatories in central Europe (e.g. France, Germany, Poland, Swi …
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1
vote
1
answer
103
views
In how far is Hipparcos data still being used?
I remember being excited when ESA launched Hipparcos in 1989 and was in operation until 15 August, 1993. Later, Gaia came into operation in 2013.
Reading What is the overlap between the Gaia and the H …
- 5,657
3
votes
How much is usually deposited in a Mars regional dust storm?
Philip R. Christensen wrote an article back in 1986 called Regional dust deposits on Mars: Physical properties, age, and history. The abstract says
Dust deposited during global storms is subsequently …
- 5,657
1
vote
How are all the intermediate images between the "lensed" and "unlensed" endpoints of this vi...
For me, it looks indeed very much like an interpolation, both from what I see and how the caption is formulated. Also: If it would be scientific simulation results, I would have expected whatever the …
- 5,657
2
votes
How far away was the binary black hole that produced GW170729?
The LIGO science collaboration site is the official source (highlighting is from me):
Of the ten BBH systems in our catalog, six have estimated distances of about a Gigaparsec (1 Gpc = 1 billion pars …
- 5,657
3
votes
0
answers
47
views
Heat map of portion of the sky visible for a given observatory on Earth?
Reading Calculating area of visible sky I started wondering which portion of the sky one could observe how long given the 3D coordinates of an observatory, and two points in time.
In other words, I wo …
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1
vote
Highest frequency that's been imaged by a radio telescope?
Some extensive search e.g. with scholar.google.com led me to a manuscript from October 2020 entitled Design and Characterization of 275-500 GHz Corrugated Horns and Optics for a Wideband Radio Astrono …
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2
votes
0
answers
34
views
Different approaches to quantify light pollution on a given location on Earth?
The question Light Pollution: what is the difference between artificial brightness and brightness and SQM made me wonder which different ways exist to directly and indirectly quantify light pollution …
- 5,657
2
votes
0
answers
59
views
What are recent discoveries with Earth-based radar telescopes?
The Wikipedia article on radar astronomy lists a few important discoveries using radar technology in general, i.e. also using space-crafts:
The following is a list of planetary bodies that have been …
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10
votes
0
answers
143
views
Spatial wind speed distribution on Mars using dune shapes?
As a fan of exometeorology (the study of atmospheres of other planets), I scanned through a whitepaper Measuring Mars Atmospheric Winds from Orbit which says
Measurements of Mars
atmospheric winds fr …
- 5,657
2
votes
Were there any images of Sanduleak -69 202 (progenitor of SN1987A) before it exploded?
Another link worth sharing comes from ESO and is called The Large Magellanic Cloud before and after SN1987A. The link mainly shows the following
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4
votes
When was H-alpha first used to observe the universe?
Seemingly easy question, but actually not trivial to answer.
Wikipedia on H-alpha as well as other entries in other encyclopedias obviously mention the Balmer series and that the spectral line was dis …
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