Questions tagged [observational-astronomy]
Questions about the techniques and practice of observing the night sky.
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Will the lunar gateway be visible for ground based (amateur) telescopes?
Due to its low apparent magnitude and large apparent diameter, astrophotographers have managed to capture the ISS not only during solar and moon transits, but even come so far as to image individual ...
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Would a nearby "Orphan planet" be detectable?
I understand that there may be large numbers of "orphan" planets not circling any star.
If there were such a planet, say the size of Jupiter, in the vicinity of the Sun, about how close ...
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How many massive black holes exist in AGN-type galaxies?
Most galaxies have a massive (i.e., $m \gtrsim 10^5$ M$_{\odot}$) black hole in their center.
Is it known 1) theoretically and 2) observationally what fraction of these massive black holes (maybe as a ...
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Are magnetic vortices capable of providing magnetic lensing when observed away from the poles
Magnetic vortices-(ESA cluster mission from observations November 2018)(article, ESA, science & exploration: 'Magnetic Vortices explain mysterious auroral beads'. An observer during Saturn's ...
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Measurement unit of coordinate systems in astronomy
Nearly all of the coordinate system I have studied in Positional astronomy use the degree system. This makes me curious about why astronomers prefer degrees over radians as we know that Radian is a ...
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How would the synodic period of Venus appear to change if both planets were moved 10 million additional miles away from the Sun?
Let us say that Earth and Venus are both moved 10 million additional miles from the sun. How would the synodic period of Venus appear to change for an observer on Earth? If 584 days is Venus' current ...
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Fourier analysis of exoplanet transit to determine the number of planets in the system
Although I think that this can be done by simply looking at the transit graph, I was wondering if a Fourier transform of a transit (basically transforming transit depth/amplitude vs time graph to ...
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Source flux in Jy + noise computation, radio astronomy
I have an image of an extended source obtained with an interferometer (after imaging the uv-data). The image consist of a certain number of pixels, with unit of Jy/beam. Somewhere on the image is a ...
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How does instrumental dispersion work?
I am trying to understand the mathematical formulation of instrumental dispersion in galaxy and star spectra. Let $x=ln(\lambda)$. Assuming that the galaxy spectra G(x) is composed of many identical ...
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How can I use the "stiff"(the library from this site; astromatic.net). I can not escape from the error[*Error*: no 2D FITS data in <MY FITS FILE>]
I try to use "stiff" library now.
This library is from astromatic.net
I follow the tutorial's example1(page 18), but It is not worked.
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Space travel to distant stars
This is more of a hypothetical question.
Say space travel at near light speed was possible, and I wanted to travel in my spaceship to some distant star many light years away. At the time and location ...
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How to show the image of the fits file what I want to see among several fits file in astrodrizzle
Before running astrodrizzle(a library that can align the fits file images), I runned "tweakreg" to update fits header.
I used the bullet cluster data(ACS/WFC's five filters and 42 exposures),...
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Need help in writing a query using ADQL (Astronomical Data Query Language)
I am trying to query Gaia archive to get the medium quality sample as mentioned in Reico-Blanco et al. (2022) Gaia Data Release 3: Chemical cartography of the Milky Way. The idea is to query the ...
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What is the story behind this supposedly incredibly detailed image of the disk of Proxima Centauri attributed to the JWST?
Etienne Klein (@EtienneKlein)'s twitter account labels them as:
Directeur de recherche @CEA_Officiel, producteur de « Science en questions » sur @franceculture, publie « L’esprit du corps »
and ...
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"Holy grail" future observation to confirm presence of neutron stars in the centers of massive, otherwise conventional stars? (Thorne–Żytkow objects)
Wikipedia's Thorne–Żytkow object begins:
A Thorne–Żytkow object (TŻO or TZO), also known as a hybrid star, is a conjectured type of star wherein a red giant or red supergiant contains a neutron star ...
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What is this object visible in the Chandra image of the Cartwheel galaxy that isn't visible in JWST image?
In the below images I aligned an image from Chandra of the Cartwheel galaxy over the image from JWST. The first is the Chandra image pasted on top, fully opaque. The second is just the JWST image, and ...
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Did de Sitter expect to disprove Ritz theory only with visual binaries?
Walter Ritz’s emission theory stated that some fraction of the velocity of an object was added to the speed of light emitted from it. Willem de Sitter pointed out a problem with this in the case of a ...
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How do stellar magnitude and integrated magnitudes compare, perceptually?
(P.S. this is naked eyed)
Magnitudes are easily defined for point-like objects i.e. stars. However, for extended objects, the "magnitudes" quoted are actually integrated magnitudes.
For ...
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Angular resolution of naked eye at night; type of vision used
It appears that most sources quote the angular resolution of the eye as 1', regardless of day and night.
For instance,
Naked eye
Seconds of Arc and the Unaided Eye
However, the following websites give ...
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Since the Hubble Constant changes over time (it's a variable parameter), why can't the conflicting values of 67.4 and 73 both be right?
Are the conflicting values from the 'early universe' (Planck) method and the 'late universe' (Distance ladder) method actually compatible? Since during the latter period of the universe 'dark energy' ...
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If I can't unscramble an egg, how do Astronomers unscramble views gravitationally lensed by complex mass distributions?
Quanta Magazine's Two Weeks In, the Webb Space Telescope Is Reshaping Astronomy highlights two submissions to arXiv soon after the first images were released: "Three days later, just minutes ...
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Measurement of Planetary Aberration (similar to stellar aberration)
It is often stated that, "Planetary aberration is a combined result of the observer's motion and the time taken for light to travel from a body in the Solar System to the observer". I am not ...
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What percentage of visible stars will JWST be able to survey over the next 10 years?
The James Webb telescope is projected to stay operational over the next 10 years. During this time, what percentage of the visible universe/stars will it be able to survey? Of course, technically the ...
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What is the large dim feature near the center of the first James Webb image (of SMACS 0723)?
I was intrigued by the large dim feature (highlighted below) in the center of the first James Webb image of SMACS 0723. Is anything known about it?
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What am I looking at when seeing through a 3nm Hα filter?
http://www.astronomyknowhow.com/hydrogen-alpha.htm
The line that appears in the red part of the spectrum is created when an electron moves between the second and third orbit (N=2 and N=3) and the ...
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Orientation of the optical telescope assembly in the Hubble Space Telescope
What is the orientation of the optical telescope assembly with respect to the direction of motion of the Hubble Space Telescope? If it happens to be in the direction of motion, does the primary mirror ...
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Calculate Earth Zenith Point of Another Planet with Azimuth and Elevation of another Observer Point
I need to find the Longitude of the closest point on Earth (zenith) to Jupiter with the Azimuth and Elevation data from another observation location at a given point in time.
Below is the source of my ...
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Identify stars in image from James Webb
This is one of the recent pictures from the James Webb released by NASA. It's a picture of the galaxy cluster SMACS 0723. It locates in the Volans constellation.
I'm trying to identify the stars in ...
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Why doesn't dark matter clump strongly in the center of galaxies, since it doesn't feel either radiation pressure or the Pauli exclusion effect?
Dark matter is described as being spread not only throughout a galaxy, but also around it in a halo of some sort that extends far beyond the visible parts of the galaxy...
In fact, dark matter haloes ...
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If you could get up close to them, what nebulae would be the most visually impressive to your naked eye?
Pop cult sci-fi movies like to show nebulae as they appear in photographs, but to a live, real-time viewer: these dazzling, snazzy and amazing backdrops to spaceship flying in front of them in real-...
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Why were only 4 days of data used in the M87 EHT observation?
I wonder why only 4 days of data were used in the M87 Event Horizon Telescope (EHT) observation. What is preventing you from obtaining a more detailed and clearer image over a longer period of time?
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Why was the NVSS(NRAO VLS Sky Survey) conducted at 1.4 GHz continuum?
I am observing the nature of some galaxies looking at their radio images and contours from NVSS. So, the data collected have radio flux at other wavelengths but I am studying it at 1.4GHz. I have been ...
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What are the Rules of Significant Figures, Precision, and Uncertainty, Strictly Speaking? [closed]
In the physical sciences (which are physics, chemistry, astronomy, materials science, etc.), we learned that the uncertainty is +/- the smallest unit (which is 1) of the last significant figure if the ...
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The constellations in “Powers of Ten”
I watched a video called Powers of Ten made in the 70s. It starts from a view of an area in Chicago and moves the "camera" away from the ground towards the space. At 3m15s of the video, the ...
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Time taken calculation to reach synodic degrees between planets
I have a software tool which calculate the synodic period with degree inputs with two planets. Synodic Period is the temporal interval that it takes for an object to reappear at the same point in ...
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Recognize the celestial object in UMa
I’m new to Astronomy observations. I took a picture from my phone of a object near beta Ursa Major and m97 which I couldn’t find (I was on low magnification), I couldn’t find out what it was. Any ...
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What can we learn from the rotation data of a star?
Knowing the speed of a star's surface rotation gives us what data and information. For example, if it is a big star, is it possible to measure distance using the doppler effect? Or can we calculate ...
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Can this ppxf fit work?
I am trying to do kinematical analysis of spectra using ppxf-algorithm from Capellari. The velocity dispersion I get seems to be to high and I am not sure what the reason could be. On the website of ...
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following several unknown phenomena detected at the edge of the solar system, is there a 5th force which acts at the edge of the solar system?
following several unknown phenomena detected as the acceleration of Oumuamua and electrons and strange data sent by traveler 1 at the edge of the solar system, is there a 5th force which acts at the ...
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Does humidity affect image formation point while observing through a telescope?
I was wondering if atmospheric humidity affects the point where an image forms through a telescope?
I have a 256mm aperture 1200mm focal length Newtonian Reflector. I generally use a 25mm eyepiece and ...
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Could "gravitational atom” black hole be detected using observation of gravitational microlensing?
D. Baumann et al., published the article hypothesizing existence of "gravitational atom” black holes (not sure whether those are just stellar ones or also those could be supermassive black holes ...
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civil twilight & sunset
Many Internet sources define civil twilight (hereinafter CT) as follows:
Any point in time at which the 'geometric center of the sun' is between 0°, inclusively, and 6°, exclusively, below the horizon ...
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Does "Angular Diameter Turnaround Point" solve the Great Wall Problem?
According to Wikipedia,
The Hercules–Corona Borealis Great Wall is the largest known structure in the observable universe, measuring approximately 10 billion light-years in length.
But since it's ...
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Is there any specific way to record observations on any celestial object while looking through a telescope? [closed]
Which aspects or factors do I take into consideration while I record observations on any celestial object?
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Method to get data from NED IPAC and NVSS, without manually giving RA/dec input
I am collecting the radio flux data at 1.4Ghz frequency for all 1544 Markarian Galaxies for a study. For that, I have to first put the names of these Markarian galaxies in NED IPAC and from there ...
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How do I phase fold the light curve for a variable star?
I have some observational data for a star where I've done aperture photometry to get a partial period. I understand that you need to use other techniques to estimate a period for stars whose period is ...
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redshift puzzle
I have the central line of the spectrum of an elliptical galaxy (NGC:4697) and a template K-star. I have calculated the redshift z by computing the crosscorrelation function between the galaxy and the ...
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Why is the summer solstice night shorter than the winter solstice day?
I was looking at the sunrise and sunset times where I live (Aberdeen, Scotland) and I noticed something odd: the time between sunrise and sunset in winter is longer than the time between sunset and ...
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Is there a cosmological model of the evolution of vacuum motion in our universe over time? [closed]
Is there a cosmological model of the evolution of vacuum motion in our universe over time?
Does this model starting from a non-vacuum constitute an advantage compared to the cosmological model of ...
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