Unanswered Questions
100 questions with no upvoted or accepted answers
1
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16
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cross-matched SDSS-WISE catalog
Please where can I find cross-matched SDSS and WISE dataset for a machine learning project?
(Galaxy-star-qso classification task)
2
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0
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59
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BVR photometry and Luminiscense
I have the values from B, V and R filters. How do I obtain the total luminescence of a star?
My ultimate aim is to find the relative masses and luminescence of various stars/galaxies in a galactic ...
- 221
3
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41
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Why MIT's Benjamin Rackham says "nearby ultracool dwarf SPECULOOS-3" would look "purplish-red, spotted, and flaring" from an airless orbiting planet?
May 15, 2024 MIT News article Newly discovered Earth-sized planet may lack an atmosphere includes the following:
“We can say from our spectra and other observations that the star has a temperature of ...
- 30.7k
2
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0
answers
51
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How to identify Hydrogen lines of slitless spectrograph of Type A9 star
Hi I am analysing slitless spectrograph of type A9 star Canopus. Here is as sample of the spectrograph.
I basically did a simple summing up of the columns and added the data (as a simple spectrum co- ...
0
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64
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0
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28
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Errors in SDSS photometry
In plotting out the magnitude errors in SDSS photometry, I get the following pattern:
Why do the errors go up to about 0.5, then down? In other words, why does it look like a high-heeled shoe (or ...
- 2,620
1
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0
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69
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magnitude calculation if a blackbody's radius and temperature are provided
I know it is necessary to convolve its spectrum with the transmission curve of a filter.
Are there any online tools or codes available for calculating a BB's magnitude in any specific band (e.g., ...
- 3,137
3
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52
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How do you calculate the reddening corrections for photometry?
I have photometric data from Gaia for a star and am trying to de-redden the colors. I need to find the reddening corrections for the photometry. I have photometry for G, BP, and RP.
To start I am ...
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1
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66
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How do you convert from the Gaia photometric system to Johnson-Cousin?
I have Gaia photometry (G, G_bp, and G_rp) and need to convert it to the Johnson Cousin system. In the Data release 3 (DR3) documentation they provide tables of how to do this but I’m very confused by ...
- 11
0
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76
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How to convert flux to flux density for a synthetic spectrum?
I have several model SEDs generated by the CLOUDY spectral synthesis code. The data is formatted with one wavelength column and one flux column. I wish to perform Hubble synthetic photometry on these ...
- 61
2
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56
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Calculate change in spectral line intensity for a change in temperature
I am trying to do some simple modelling of spectral line emission. I am starting with some ALMA observations of a protoplanetary disk, where the emission from a particular molecule at frequency 344GHz ...
- 1,386
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What is a good resource for finding accurate apparent magnitudes stars in different filters?
I am unable to find this information online, does anyone know of a database, book, or website that contains all of the B-band, V-band, I-band etc.... apparent magnitudes for each star?
Thanks for any ...
- 121
3
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104
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SExtractor parameters for identifying Star Forming regions
I am using SExtractor (Source Extractor) to identify Star-Forming regions in a galaxy. The problem is I am unable to choose the parameters required for it. SExtractor is just a tool to identify the ...
- 327
3
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0
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78
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What instruments do amateur astronomers use in their ground based telescopes in order to avoid atmospheric absorption/telluric contamination?
What instruments do amateur astronomers use in their ground based telescopes in order to avoid atmospheric absorption/telluric contamination? For example, when an astronomer observes a celestial body ...
- 1,624
2
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60
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What could these LMC objects in this color-color diagram be?
I have performed a color-color and colour-magnitude plot of various sources detected in an LMC image (JWST NIRCAM F200W, F150W and F115W filters). I then also queried SIMBAD to collect relevant ...
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