Askaniy
@askaniy.bsky.social
Astronomy student, Python programmer, occasional artist
Great result! What color space and white point were used? Was the conversion via CIE XYZ space, or were CIE RGB color matching functions used directly? Or was RGB represented by slices of the spectrum at some wavelengths?
September 4, 2025 at 4:44 PM
Great result! What color space and white point were used? Was the conversion via CIE XYZ space, or were CIE RGB color matching functions used directly? Or was RGB represented by slices of the spectrum at some wavelengths?
(About the contrast: the attached GIF is for IR, where the limb darkening is stronger, and the effect is comparable to dark spots. In the visible range the limb darkening is weaker, and the spots can have fine structures that increase the contrast, according to the modeling)
September 2, 2025 at 2:56 PM
(About the contrast: the attached GIF is for IR, where the limb darkening is stronger, and the effect is comparable to dark spots. In the visible range the limb darkening is weaker, and the spots can have fine structures that increase the contrast, according to the modeling)
Great!
The preprint inspired me to explore what this system might look like to the human eye, it is definitely crazy: bsky.app/profile/aska...
The preprint inspired me to explore what this system might look like to the human eye, it is definitely crazy: bsky.app/profile/aska...
Giant planets orbiting red dwarfs are uncommon, as are hot Neptunes ("Neptunian desert"), as are exoplanets in polar orbits. On this painting, the host star "observes" its strange planet through a massive polar dark spot.
[1/9] of the "art research" thread on TOI-3884 and "red" dwarfs in general.
[1/9] of the "art research" thread on TOI-3884 and "red" dwarfs in general.
September 2, 2025 at 2:47 PM
Great!
The preprint inspired me to explore what this system might look like to the human eye, it is definitely crazy: bsky.app/profile/aska...
The preprint inspired me to explore what this system might look like to the human eye, it is definitely crazy: bsky.app/profile/aska...
Observations indicate that flare spectra resembles that of class A stars in the visible range [DOI 10.1088/0067-0049/207/1/15]. Flares are detected at high latitudes [DOI 10.1093/mnras/stab2159]. I assume them to be similar in appearance to White-Light Flares on the Sun.
[9/9]
[9/9]
August 10, 2025 at 5:08 PM
Observations indicate that flare spectra resembles that of class A stars in the visible range [DOI 10.1088/0067-0049/207/1/15]. Flares are detected at high latitudes [DOI 10.1093/mnras/stab2159]. I assume them to be similar in appearance to White-Light Flares on the Sun.
[9/9]
[9/9]
The final composite art with the planet uses limb darkening profile computed via LDTk [https://github.com/hpparvi/ldtk], a Python library. Interestingly, for a star with these parameters, the darkening occurs without reddening.
[8/9]
[8/9]
August 10, 2025 at 5:08 PM
The final composite art with the planet uses limb darkening profile computed via LDTk [https://github.com/hpparvi/ldtk], a Python library. Interestingly, for a star with these parameters, the darkening occurs without reddening.
[8/9]
[8/9]
The texture's color was calculated using TCT and calibrated with CTC [https://github.com/Askaniy/CylindricalTextureCalibrator] to match the hue of Proxima Centauri [DOI 10.1051/0004-6361/201730582]. Hand-painted in Krita.
[7/9]
[7/9]
August 10, 2025 at 5:08 PM
The texture's color was calculated using TCT and calibrated with CTC [https://github.com/Askaniy/CylindricalTextureCalibrator] to match the hue of Proxima Centauri [DOI 10.1051/0004-6361/201730582]. Hand-painted in Krita.
[7/9]
[7/9]
Based on the illustrations of this study, I drew a texture map of TOI-3884 (11 d period). Its polar dark spot was explored thanks to the transiting planet. Texture contrast (after Gaussian blurring) aligns with the spot contrast described in [DOI 10.48550/arXiv.2506.11998].
[6/9]
[6/9]
August 10, 2025 at 5:08 PM
Based on the illustrations of this study, I drew a texture map of TOI-3884 (11 d period). Its polar dark spot was explored thanks to the transiting planet. Texture contrast (after Gaussian blurring) aligns with the spot contrast described in [DOI 10.48550/arXiv.2506.11998].
[6/9]
[6/9]
Instead of granules, red dwarfs have structures like "inter-granular lanes" and polar dark spots. Their presence depends on mass, period, etc. [DOI 10.1088/2041-8205/813/2/L31] modeled global structure for a star with 20 d period and revealed a massive polar dark spot.
[5/9]
[5/9]
August 10, 2025 at 5:08 PM
Instead of granules, red dwarfs have structures like "inter-granular lanes" and polar dark spots. Their presence depends on mass, period, etc. [DOI 10.1088/2041-8205/813/2/L31] modeled global structure for a star with 20 d period and revealed a massive polar dark spot.
[5/9]
[5/9]
Convective granules are nearly invisible due to high log g and low T_eff. Additionally, TOI-3884 lies precisely at the minimum granulation contrast threshold (approximately 3%, compared to 16% on the Sun) [DOI 10.1016/j.jcp.2011.09.026, figure 11].
[4/9]
[4/9]
August 10, 2025 at 5:08 PM
Convective granules are nearly invisible due to high log g and low T_eff. Additionally, TOI-3884 lies precisely at the minimum granulation contrast threshold (approximately 3%, compared to 16% on the Sun) [DOI 10.1016/j.jcp.2011.09.026, figure 11].
[4/9]
[4/9]
Red dwarfs are often misperceived as red, but color calculations with github.com/Askaniy/True... show that absorption lines in spectra typically make them yellow. Also, “blue depression” spectral feature [DOI 10.1093/mnras/stad1391] falls on sensitivity range of blue cones.
[3/9]
[3/9]
August 10, 2025 at 5:08 PM
Red dwarfs are often misperceived as red, but color calculations with github.com/Askaniy/True... show that absorption lines in spectra typically make them yellow. Also, “blue depression” spectral feature [DOI 10.1093/mnras/stad1391] falls on sensitivity range of blue cones.
[3/9]
[3/9]
TOI-3884 b has a radius of 6.4 R⊕, a mass of 33 M⊕, and T_eff ≈ 460 K (Mercury-like thermal regime). Classified as Sudarsky class III, the planet is likely cloudless. It orbits TOI-3884 (TIC 86263325), an M4-type star with 0.3 R☉, 0.3 M☉, and T_eff ≈ 3000 K.
[2/9]
[2/9]
August 10, 2025 at 5:08 PM
TOI-3884 b has a radius of 6.4 R⊕, a mass of 33 M⊕, and T_eff ≈ 460 K (Mercury-like thermal regime). Classified as Sudarsky class III, the planet is likely cloudless. It orbits TOI-3884 (TIC 86263325), an M4-type star with 0.3 R☉, 0.3 M☉, and T_eff ≈ 3000 K.
[2/9]
[2/9]
Meanwhile, Bolin et al. 2025 (arxiv.org/abs/2507.05252) obtained much more blue results:
July 8, 2025 at 1:21 PM
Meanwhile, Bolin et al. 2025 (arxiv.org/abs/2507.05252) obtained much more blue results:
Nice paper! I've just traced the plot and calculated colors based on it. All the spectral data agree well.
(Also, I would be very grateful if you could share the original spectrum.)
bsky.app/profile/aska...
(Also, I would be very grateful if you could share the original spectrum.)
bsky.app/profile/aska...
Reflectance colors of 3I/ATLAS in sRGB color space with illuminant E (assuming 0.5 albedo, it's very likely lower)
July 8, 2025 at 12:50 PM
Nice paper! I've just traced the plot and calculated colors based on it. All the spectral data agree well.
(Also, I would be very grateful if you could share the original spectrum.)
bsky.app/profile/aska...
(Also, I would be very grateful if you could share the original spectrum.)
bsky.app/profile/aska...
Seligman et al. 2025: arxiv.org/abs/2507.02757
Opitom et al. 2025: arxiv.org/abs/2507.05226
Spectral reconstruction and extrapolation with TrueColorTools:
Opitom et al. 2025: arxiv.org/abs/2507.05226
Spectral reconstruction and extrapolation with TrueColorTools:
July 8, 2025 at 11:51 AM
Seligman et al. 2025: arxiv.org/abs/2507.02757
Opitom et al. 2025: arxiv.org/abs/2507.05226
Spectral reconstruction and extrapolation with TrueColorTools:
Opitom et al. 2025: arxiv.org/abs/2507.05226
Spectral reconstruction and extrapolation with TrueColorTools:
Beautiful work!
I recently reviewed papers on Hot Jupiters and attempted my own interpretation: bsky.app/profile/aska...
I recently reviewed papers on Hot Jupiters and attempted my own interpretation: bsky.app/profile/aska...
An attempt to (relatively) realistically paint a hot Jupiter with a quasi-closed type of atmosphere, according to Bisikalo et al. 2021. (ui.adsabs.harvard.edu/abs/2021PhyU...)
July 8, 2025 at 7:32 AM
Beautiful work!
I recently reviewed papers on Hot Jupiters and attempted my own interpretation: bsky.app/profile/aska...
I recently reviewed papers on Hot Jupiters and attempted my own interpretation: bsky.app/profile/aska...
The color of the photometric surface is blue according to modeling (Sudarsky et al. 2000 for example) and measurements (Evans et al. 2013 for example), but mostly overexposed here. The color of the upper atmosphere is blue due to Rayleigh scattering.
May 4, 2025 at 9:35 AM
The color of the photometric surface is blue according to modeling (Sudarsky et al. 2000 for example) and measurements (Evans et al. 2013 for example), but mostly overexposed here. The color of the upper atmosphere is blue due to Rayleigh scattering.
For hot Jupiters, the L1 point is just within a few planetary radii, so it's easy for the atmosphere to escape inward. With a lower semi-major axis, the speed is higher, so it goes in the direction of motion. But solar wind can stop the leak and form a quasi-closed configuration.
May 4, 2025 at 9:35 AM
For hot Jupiters, the L1 point is just within a few planetary radii, so it's easy for the atmosphere to escape inward. With a lower semi-major axis, the speed is higher, so it goes in the direction of motion. But solar wind can stop the leak and form a quasi-closed configuration.