Questions tagged [time-domain-astronomy]

For questions relating to the study of how and why objects in the cosmos change on timescales from seconds to decades, both in photometric and spectroscopic datasets. Not for questions about the nature of time. There may be a more specific tag, such as variable stars or supernovae

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Can a Nova occur outside of a binary star system?

With the T Coronae Borealis nova likely to erupt soon, it got me thinking if novas could occur outside of a binary star system. On the wiki page titled Nova: All observed novae involve white dwarfs ...
Shawn Lim's user avatar
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2 votes
1 answer
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Automated (and hopefully free) systems I can subscribe to sending email or SMS text message when the T Coronae Borealis Nova becomes visible?

My earlier question about predicted potentially observable events Has a gravitational microlensing event ever been predicted? If so, has it been observed? is limited to microlensing. Now I have just ...
uhoh's user avatar
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1 vote
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Is there such a thing as a map that shows the current (not observed) positions of celestial objects?

As I understand it, maps of the sky and three-dimensional maps of the universe all show the observed positions of celestial objects. Are there any maps that show our best guess at their current ...
John Wu's user avatar
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5 votes
0 answers
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If a Milky Way supernova were to happen, how long would it take for astronomers to be notified?

If a Supernova were to happen in the Milky Way, how long would it take for astronomers to be notified? How long would it take for the people running the gravitational wave and neutrino detectors to ...
blademan9999's user avatar
6 votes
1 answer
584 views

Intuitive connection between the periods of oscillation of Betelgeuse and the elemental concentrations at its core? (Betelgeuse; Saio et al. (2023))

Preamble (yes it's long, but it's part of this question's premise, so need to spell it out) Dr. Becky's recent video New study claims Betelgeuse supernova IMMINENT (decades not centuries!) | Night Sky ...
uhoh's user avatar
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4 votes
1 answer
523 views

Has the new type II supernova SN 2023ixf's subtype been determined yet, and is a tentative light curve possible? Is it still getting brighter?

Wikipedia's article on SN 2023ixf begins: SN 2023ixf is a type II (core collapse) supernova located in the Pinwheel Galaxy (M101). It was first observed on May 19, 2023 by Koichi Itagaki and ...
uhoh's user avatar
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2 votes
0 answers
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History, significance and "drama" (if any) of T-Tauri stars, especially the early bits?

In this answer to Can I write a systematic review as an undergraduate and get it published in a journal? in Academia SE I recounted my memory of an experience from circa 1980: I had an initially ...
uhoh's user avatar
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4 votes
2 answers
83 views

Are chirped gravitational wave events generally first identified by searching through libraries of chirps?

Comments below What does "GPU-accelerated butterfly matched filtering over dense bank of time-symmetric chirp-like templates" mean? (GW170817) suggest that for this technique a library of ...
uhoh's user avatar
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7 votes
2 answers
215 views

How close are we to observing all of the sky all of the time?

I was musing on how amateur astronomy is still a heavy contributor to the overall field, and how on any given night there will be plenty of small telescopes pointing into the void and capturing the ...
Ingolifs's user avatar
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How to derive gravitational-wave frequency vs time from strain vs time

Suppose I have a time-series of the gravitational-wave strain amplitude as a (discrete, i.e., an array of numbers) function of time. The figure below is just illustrative. I am not using measured LIGO/...
Daddy Kropotkin's user avatar
3 votes
1 answer
110 views

What is the fraction of the time that the JWST could view a short transient event on-demand as a function of position on the celestial sphere?

In this answer to Why does JWST have such a big Blind Spot? I argue that this space telescope primary relationship with time is that it strives to look way back in it and so as long as a given ...
uhoh's user avatar
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13 votes
2 answers
4k views

Why is the L3 Lagrangian point not perfectly stable? And why is the Earth-Sun L3 point a bit less than one A.U.?

I suppose the answer might involve general relativity, but still.... The L4 and L5 points are considered, theoretically, long-term stable, but not L3, on the exact opposite side of the Sun... And it ...
Kurt Hikes's user avatar
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1 answer
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How much time do I have left to easily spot the recently brightened Recurrent Nova RS Ophiuchi with binoculars and mild light pollution?

Excellent answers to Binocular-friendly star map to find the Recurrent Nova RS Ophiuchi? provide some helpful maps for circa 8° FOV binoculars, but due to spatial and potential meteorological ...
uhoh's user avatar
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1 vote
0 answers
91 views

What is a typical "pulse rate" for a black hole "heartbeat"? Is the process better understood than it was in 2011?

The 2011 NASA Goddard video NASA | RXTE Detects 'Heartbeat' Of Smallest Black Hole Candidate mentions a heartbeat and includes a graphic of pulses from GRS 1915+105. A screenshot is shown below. No ...
uhoh's user avatar
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5 votes
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Is "magnetars don't last long — just a year to a few years" really true? Is it a misquote or perhaps taken out of context?

NASA's Two Sides of the Same Star discusses the relationship between pulsars and magnetars and contains a video also linked below. At 02:13 it quotes "Tom ...
uhoh's user avatar
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21 votes
4 answers
3k views

Can you see something active in the sky apart from satellites? Can there be amateur time-domain astronomy?

What I mean is an event unfolding that is viewable by naked eye or telescopes, and doesn't take comparing days of footage to see moving pixels. Apart from satellites, is there something that moves or ...
Firsh - justifiedgrid.com's user avatar
2 votes
0 answers
158 views

Are astronomers still using photomultiplier tubes for optical photometry?

In Time domain astronomy and fastest eclipsing binary ZTF J1539+5027 (+20 mag, 6.91 minutes) How to measure it's minimum brightness? I've written A logarithmic magnitude scale might tend to show ...
uhoh's user avatar
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3 votes
1 answer
152 views

Time domain astronomy and fastest eclipsing binary ZTF J1539+5027 (+20 mag, 6.91 minutes): How to measure its minimum brightness?

Per Wikipedia's ZTF J153932.16+502738.8 ZTF J153932.16+502738.8 is a double binary white dwarf with an orbital period of just 6.91 minutes. [...] The light curve shows eclipses. One dip in the light ...
uhoh's user avatar
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1 vote
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In what ways are neural net classifiers "better" than search algorithms for eclipsing star system searches? (1D time series, not images of cats)

Neural net classifiers are both "hot" and useful. TIC 168789840: A Sextuply-Eclipsing Sextuple Star System is quite an interesting read, and describes the use of one trained on a ...
uhoh's user avatar
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3 votes
2 answers
194 views

Do ASKAP and ALMA have "fast dump" interferometric modes? Can they see and perhaps report Fast Radio Bursts in real time?

Chatterjee et al 2017 The direct localization of a fast radio burst and its host nicely shows a VLA detection of a repeating FRB in 5 millisecond steps nicely demonstrating the dispersion slope ...
uhoh's user avatar
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0 votes
1 answer
170 views

The definition of eclipsing binary star systems

In the second minimum (the 3rd step) there is a smaller decrease in light intensity. For this to happen, wouldn't you need to be looking at the plane of orbit from above rather than directly along the ...
XXb8's user avatar
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2 votes
0 answers
213 views

Sinusoidal Light curve of an eclipsing binary [closed]

This light curve seems really weird to me, I'm used to seeing light curves where the barycenter is a straight line. It either stays at a place, moves at a constant speed or slowly increases its speed. ...
Arnab Chowdhury's user avatar
7 votes
2 answers
176 views

Observing eclipsing binaries

In a matter of weeks, I will be performing my first observation using a 25-cm Newton telescope (+CCD camera) and would be grateful for advice regarding an otherwise basic research that I have decided ...
Spikes's user avatar
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2 votes
1 answer
214 views

Which data should I use to take the fast Fourier transform (FFT) to find time period for eclipsing binaries?

I am trying to use Kepler Data for Eclipsing Binaries to estimate time period, and then other parameters such as mass, eccentricity, semi-major axis, distance, etc. of the system. I want to write code ...
ruskin23's user avatar
22 votes
1 answer
588 views

Multi-messenger astronomy: what is the potential of simultaneous detection of gravitational waves and neutrinos from a supernova?

Thanks to the efforts of the aLIGO team, gravitational wave astronomy is a reality. At the same time, neutrino detectors like Hyperkamiokande are becoming much more sensitive. My question is: what ...
ProfRob's user avatar
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1 vote
1 answer
567 views

period of an eclipsing binary

I am confused about the definition of the period of an eclipsing binary, a binary configuration where one component crosses the other across the line of sight. When people say that an eclipsing binary ...
Orbifold's user avatar
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