Unanswered Questions
164 questions with no upvoted or accepted answers
16
votes
0
answers
256
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What 1° x 1° region is the optically darkest patch in the sky?
What 1° x 1° region of the night sky has the lowest flux of light?
(considering the typical visual/luminance filter range, approximations using other filters/bands are acceptable, but should be in the ...
10
votes
0
answers
509
views
What are the analysis steps in taking raw data from Kepler to a planetary system determination
I wish to get a concise list of the analysis steps required to take raw light data from a Kepler data set of a star through the steps needed to get to an analytical determination of the existence of a ...
- 1
6
votes
0
answers
194
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What are the pros and cons of different types of echelle spectrograph cross-dispersers?
Echelle spectrographs, operating at high resolving power, typically consist of an echelle grating with a low numbers of lines/mm, used with high diffraction orders (often $n=$50-100). To separate the ...
- 30.7k
6
votes
0
answers
119
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Need help understanding stellar spectroscopy data from ESO
The European Southern Observatory webpage has a web page that has tabular spectrogram data from A. J. Pickles, University of Hawaii. There are over 130 .dat files there. Each one represents a ...
- 161
6
votes
1
answer
189
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Do narrow lines in the spectra of O- and B- type stars always indicate magnetic fields?
I was reading a paper on the differential emission measures of a set of hot O- and B- type stars. As the authors discuss in Section 3 (page 959), two stars, $\tau$ Sco and $\theta^1$ Ori C, have ...
CommunityBot
- 1
5
votes
0
answers
150
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Is it possible to narrow down possible dates for the following eclipse pattern?
I am searching for an year which satisfies the following criteria.
Dates are in Gregorian calendar.
Criteria
Year range 3800 BC to 500 BC
Solar Eclipse of any kind between October 14 and October 22 ...
- 199
5
votes
0
answers
79
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Obtaining the derived period of $\omega$ Canis Majoris
I have read these two papers:
On the nature of the Be phenomenon I. The case of ω Canis Majoris
Stellar and circumstellar activity of the Be star ω CMa
II. Periodic line-profile variability
In the ...
- 555
5
votes
0
answers
457
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Why does titanium oxide around Betelgeuse produce this particular sawtooth-shaped absorption spectrum?
Betelgeuse Just Isn’t That Cool: Effective Temperature Alone Cannot Explain the Recent Dimming of Betelgeuse suggests that the recent dimming might be caused by increased optical absorption by dust ...
- 30.7k
5
votes
0
answers
225
views
How to apply Fast Folding algorithm?
I have High Time Resolution Universe dataset. I have applied de-dispersion on this HTRU dataset, and thereafter I applied the folding function to fold the dataset.
How I can find that the periodicity ...
- 6,300
5
votes
0
answers
124
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"Extinct Species" of meteorite - how quantitative is the statistical analysis?
This recent paper in Nature A new type of solar-system material recovered from Ordovician marine limestone is available to read on line, and Figure 3 is already widely publicized.
Comparison of ...
- 30.7k
4
votes
0
answers
82
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I was finding the period of crab pulsar using efsearch(xronos)
I was finding the period of crab pulsar(one orbit data from ASTROSAT/laxpc) using efsearch (heasarc/xronos). Despite considering period = 33ms, I am not getting sharp peaks at higher Resolution for ...
- 101
4
votes
0
answers
52
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How does SDSS estimate photometric redshift of sources?
I'm looking through the data in SDSS DR 12:
...
- 2,620
4
votes
0
answers
54
views
What happens to the non-fusion formed metals in stars?
Let’s consider a population I star of some given metallicity.
I know that depending on the type of star, different structures are possible with convection zones and radiative zones trading around ...
- 3,404
4
votes
0
answers
60
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How are plage regions related to the density of medium and velocity FeII ions?
During a literature review (abstract), I found that the intensity of FeII (298.5 nm) ions in the last solar minimum was higher than the two previous solar minima 21 & 22. The velocity of FeII ions ...
- 30.7k
4
votes
0
answers
160
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Time evolution data of the Great Red Spot on Jupiter?
Jupiter's Great Red Spot fascinates scientists for ages, so it does me. Where can I find a table (e.g. as CSV-file) with the time evolution of longitude, latitude, horizontal and vertical extension of ...
- 30.7k