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Questions tagged [observation]

Questions regarding the action or process of observing a single object carefully to glean information.

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Why do we use filters in telescopes for astronomical imaging?

I have read that if we image without a filter we get no information about the color or SED of objects. Can anyone elaborate the reasons for using filters for imaging/photometry? What happens if we ...
9
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2answers
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After Oumuamua passage, has an “urgency” telescope time request procedure been set up?

During the rapid passing of ʻOumuamua through our solar system, it was difficult to get instant telescope time. Usually, formal requests and a review process are necessary before telescope time is ...
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1answer
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What is it exactly about these flares of infrared light from Sgr A* that “confirms” it is a supermassive black hole?

CNET.com's SCI-TECH Scientists confirm a 'supermassive black hole' at the heart of our galaxy It's "mind-boggling", they say. This links to Astronomy.com's Scientists finally confirm the Milky Way ...
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My family saw small dots in the sky moving rapidly at night [duplicate]

My family and I saw small dots moving rapidly from north to south that flew in a V formation (the kind that ducks fly in). There aren't any ducks in my country. This phenomenon appeared twice. They're ...
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1answer
61 views

How far can a planet with living beings get before we cannot see the living beings? [duplicate]

Let there be a planet with Earth-like life. However, no trash or monuments or other visible structures, just organisms. How far can that planet be from Earth before our equipment just cannot observe ...
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1answer
51 views

Solar series 142 and 147 started same year - series 147 and 152 will be ending same year. Why? Coincidence?

This question was left over from the last question I had, so I am asking it separately here: I have been looking into two solar eclipses (Saros series 147 and 152) that will both be occurring in 2021....
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1answer
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Why the blank wedges in this very early 21 cm map of the Milky Way? (Oort et al. 1958)

Jan Oort was a pioneer in radio astronomy. Wikipedia says: It has been written that “Oort was probably the first astronomer to realize the importance” of radio astronomy. “In the days before radio ...
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1answer
35 views

What is a “semester series” for eclipse prediction? - Solar saros series 147 and 152

Yet again, I just stumbled across another baffling eclipse question (actually, two now). I was interested in two eclipses (Saros series 147 and 152) that will both be occurring in 2021. Each of these ...
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32 views

How to compare the observation with the theoretically predicted result?

On the Wikipedia Article on “Geodesics in general relativity”, it says the following: “Thus, for example, the path of a planet orbiting a star is the projection of a geodesic of the curved 4-D ...
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2answers
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Planning observation: determine dates where moon is within 30 degrees of my object?

I'm planning an observation for a proposal and I need to determine which dates the moon is within 30 degrees of an object so I can ask to not be scheduled for those dates. This object is near the ...
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1answer
44 views

Throughout the year, are all parts of the night sky visible from any given point on Earth?

Or are there points on Earth where certain parts of the 360° night sky are never visible throughout the whole year? Depending on the answer to this question, are there points on Earth where parts ...
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White star sized bright flashes and curved streaks [duplicate]

Yesterday Sept 11th around 0930-1030 pm in northern Wisconsin, me and my girlfriend were star gazing. Straight up in plain view, we were watching a satellite (blinking and way higher in the atmosphere ...
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1answer
63 views

What phenomenon causes “lunar waves”?

In multiple video clips of the moon but also one of Jupiter, some kind of waves can be observed. Is this just the effect of the object moving behind layers of different refractive indexes (similar to ...
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0answers
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Are Saros series separated by “40” in numbering related in any way?

Can anyone help with this question? My question arose from an eclipse related observation that I made while looking into lunar Saros series 129. It is the Saros series number for the lunar eclipse ...
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2answers
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Why is sunset on 21st of June not the latest?

Why is the sunset not the latest on 21 June, but only on 27 June. Purely geometrically regarding the orbit of the two celestial bodies this should not be like this? Is there somewhere a good source, ...
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2answers
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Does the edge of the Universe travel faster than the speed of light?

The Universe is expanding faster than the speed of light then does that mean matter at the edge of the universe is also traveling at the speed of light or are ether opposite sides of the universe are ...
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In the JPL small body browser, why is uncertainty on absolute magnitude “N/A”?

In the JPL small body browser, orbital elements are all provided with uncertainties and even a covariance matrix, such as for 2013 LA2. Very good. But underneath, the absolute magnitude is reported ...
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1answer
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Fundamental axioms in LCDM

What are the axioms (if any) behind the LCDM model of cosmology? NB: axioms, not postulates (e.g., inflation)
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Is Mars brightest from Earth at opposition, perihelion or somewhere in between?

After reading this article, I was inspired to run some simulations at NASA's JPL Solar System Simulator to see Earth's and Mars' orbits from above. From what I could visually determine (from the JPEG ...
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3answers
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Why do we use solar filters instead of simply reducing aperture of the telescope?

Everywhere I read that to view the Sun in the telescope, one has to use a solar filter. The filter must be handled carefully to avoid any holes in it and even mustn't be stretched so as to avoid ...
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0answers
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Asteroseismology; recordings of star vibrations duration and data availability?

A short video titled "Why Tess is recording the "sounds of stars" at the bottom of the page of the BBC News article Planet-hunter launches from Florida gives a short description of Asteroseismology by ...
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1answer
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How did TESS scientists choose which stars to observe at a “2 minute cadence” in each field?

The BBC news podcast Science in Action episode New Planet Hunting Mission covers the upcoming TESS mission between 01:00 and 07:15 with Sara Seager, TESS deputy ...
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What is the canonical method to calculate the surface brightness limit of a 2D image, e.g., in a 1 arcsec2 aperture?

What is the canonical method to calculate the surface brightness limit of a 2D image, e.g., in a 1 arcsec2 aperture? ...if image has erg/s/cm2 units and each pixel has some arcsec2 dimension.
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1answer
141 views

What is equation of straight line for a ideal blackbody on the color color diagram?

The color-color diagram is a plot between $U-B$ vs $B-V$ values. For a ideal blackbody, what is the equation of this line? In other words, what does the linear relation between $U-B$ and $B-V$ look ...
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Non-typical Secondary Mirror in 20" RC telescope?

We recently discovered that the secondary mirror of our 20" RC has a hole that runs through the center. On the side of the secondary facing the primary there is a metal tube (for lack of a better ...
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1answer
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What are these “nonstandard format” lines in Distant Artificial Satellites Observation circulars?

Mike G's great answer clued me in on how to find the collection of astrometric observations of spacecraft which is maintained by the Minor Planet Center. I've noticed that there are nonstandard ...
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1answer
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Does this amateur observation hold a record even including robotic searches for supernovae?

The new paper in Nature A surge of light at the birth of a supernova (doi:10.1038/nature25151) describes the fortuitous capture of a supernova "Shock Breakout" - the earliest rise in brightness of a ...
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1answer
370 views

Where might astrometric observations of the Roadster spacecraft be catalogued?

above: (see small red lines near center of image) Tesla Roadster. 18 Feb. 2018, 11:28 UT. The image above comes from the average of ten, 300-seconds exposures, remotely taken with the 16”-f/3.75 ...
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1answer
146 views

Might the SpaceX Roadster intercept any ongoing surveys?

There are star survey telescopes in space, and on Earth. I don't really know how to begin to know where they will all be looking for the next few months. On the off-chance that someone does, or can ...
4
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1answer
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How do observational astronomers manage streaks and other artifacts from objects in Earth Orbit?

There are thousands of satellites and spent rocket parts in low earth orbit (LEO). Mostly near the lines of dawn and dusk they can be in sunlight while observatories below are still viewing the night ...
3
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1answer
160 views

How do I adjust the sunrise equation to account for elevation?

I have been working with the sunrise and sunset formula, using the equations from Wikipedia. The problem is that, in my usage thereof, it seems that it only works for sea level; if I start with ...
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How do you find the positions of celestial objects in the sky?

I want to write a program which, when given a date, a time, latitude and longitude, returns a list of the planets, Messier objects and NCC catalogue objects what are visible in the sky at that time ...
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1answer
237 views

Will time that moon crosses meridian always be periodic?

If I observe the moon pass my celestial meridian at a specific north polar clock 'time' will I observe every subsequent passage at ( 'current time' + 13.2* X 'days passed' mod 360* ) ? Does the moon ...
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1answer
60 views

Altitude of Midnight Satellite?

The other night, I observed what I believe must have been a satellite, however it was at 1:30am so I was not sure that this would be possible. Being in the Southern Hemisphere we are just past Summer ...
2
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1answer
172 views

What should be the declination of a star to be marginally circumpolar given the latitude & height from ground?

If I'm given the latitude, I can easily find the declination by using declination = 90 - latitude. I can also find the angle of dip from the height but should I add or subtract it from the declination ...
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What is the name of a device for detecting moving objects? [duplicate]

A while ago I saw a report on TV, where an astronomer described a device that was used for detecting movement of stellar objects (mainly asteroids, I think) before the age of computers. In order to ...
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1answer
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Occultations of Triton

I've been listening to an episode of the "NASA in Silicon Valley" podcast about the SOFIA mission. One of the techniques they use at SOFIA is stellar occultations to study different objects. My ...
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1answer
65 views

How well can the Sun's surface be resolved by an observatory?

There's no lack of photons, how well could a telescope resolve Sun spots and other surface features of the Sun? How would a high resolution Solar (space) telescope differ from for example Hubble which ...
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2answers
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what magnification is required to see jupiter, saturn, venus and mars with a 50mm refractor scope with f/12 ratio and 600mm focal lenth

i have a beginner telescope of 50mm and want to see planets it is arefractor with f/12 ratio and two eyepieces of 5mm and 10mm and i want to see mars, Jupiter, Saturn and venus. my max zoom ix 120x ...
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2answers
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Converting FITS (NuSTAR) coordinates to WCS

I'm trying to convert some pixel coordinates I have into WCS coordinates, ideally into a WCS region for use in some further analysis. So far I've been able to load and parse a NuSTAR FITS file, do ...
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2answers
160 views

Did Tycho Brahe improve measurements twentyfold?

I am reading a book on the Coopernican Revolution where the author states that Tycho Brahe was able to make twenty times more accurate measurements than any of his predecessors. On the other hand, I ...
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Which physical quantity is the real/definitive tracer of galaxy evolution? [closed]

Which physical quantity is the real / definitive tracer of galaxy evolution? Let me explain better: if you aimed at understanding as much as possible about the evolution of galaxies and you had to ...
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0answers
29 views

Any method to apply inverse TPoint model?

I have an automated telescope that I have written some software for. I am currently using TPoint to compensate for some of the irregularities of my system. However with TPoint you apply an offset (...
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2answers
154 views

What kind of a visual trajectory would an asteroid have if it were to hit Earth?

Let's say that Peter has a set of superb telescopes and he's watching the sky every night, for 3-4 months. He may not know it just yet, but there is an asteroid heading towards Earth, on a crash ...
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1answer
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What is the physical geometry of this apparent “eclipse” of a tiny moon of Asteroid Florence?

Below is a small GIF made from a small subset of images contained in the original 36MB GIF found at https://cneos.jpl.nasa.gov/images/news/florence.p5us.1Hz.s382.sep01.gif as I just found in the Sky ...
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1answer
638 views

Group of satellite like objects moving through the sky in a formation [closed]

This evening while siting in the garden I saw an unusual group of light objects in the sky. On their own each of the 5 objects would look like a satellite and I would not give it a second thought. ...
4
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1answer
68 views

Based on the smallest number of photons that can deliver information about a star, what is the largest size of the universe?

I was watching a summary video about the Banach-Tarski paradox and it led me to a question. If I (a) assume the universe is infinite and (b) assume it is possible to receive a single photon of light ...
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Why does the cloud of Orion Nebula appear more distinct when I am not directly looking at it?

I have a 6cm aperture newtonian refractor telescope through which I saw the Orion Nebula yesterday night. As all you can hope with a telescope of such a small aperture, I saw some faint cloudy ...
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1answer
82 views

finding Dec and R.A of a star by having Dec and R.A of another star

How can we find Dec and R.A of a star by having Dec and R.A of another star. For example in the following picture , we have that for Errai (Dec: 77 , R.A 23H 40M). How can we find Dec and R.A of ...
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1answer
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What do “star noise” and “sky noise” refer to for TESS (Transiting Exoplanet Survey Satellite)?

The eoPortal article for TESS (Transiting Exoplanet Survey Satellite) gives a fairly in-depth summary of the space telescope design and planned operation. Some further background information on its ...