J/A+A/710/A273 Habitable zones of exoplanet host stars (Gatuzz+, 2026)
Mapping X-ray conditions in habitable zones of exoplanet host stars with
SRG/eROSITA.
Gatuzz E., Rukdee S., Freund S., Kallman T., Stelzer B.
<Astron. Astrophys. 710, A273 (2026)>
=2026A&A...710A.273G 2026A&A...710A.273G (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; X-ray sources
Keywords: planets and satellites: atmospheres - planet-star interactions -
X-rays: stars
Abstract:
Stellar high-energy radiation is a key driver of atmospheric erosion
and evolution in exoplanets, directly affecting their long-term
habitability. We present a comprehensive study on stellar high-energy
radiation and its impact on exoplanetary atmospheres, leveraging data
from the eROSITA telescope array aboard the Spektrum Rotgen Gamma
(SRG) satellite. Our sample consists of 3750 main-sequence stars
identified by cross-matching with Gaia DR3. Utilizing X-ray spectral
fit s from the eROSITA catalog, we computed X-ray (LX) and combined
extreme-ultraviolet (EUV) luminosities (LEUV), derived from scaling
relationships, which we us ed to derive soft X-ray flux (XUV) fluxes
at the habitable zone (FXUV,HZ). We find that the majority of stars
in our sample are significantly more XUV-active than the Sun, with
habitable zone fluxes ranging from 10^0 to 105erg/cm2/s. The
ratio of LXUV/Lbol is found to be higher for cooler, magnetically
active stars, highlighting their potentially hazardous nature for
planetary atmospheres. Applying the energy-limited escape model, we
computed atmospheric mass-loss rates for hypothetical Earth-like
planets located at the habitable zone of each star. We also present
local maps for distances up to 500pc of the average XUV flux,
revealing "hazard zones" where stellar radiation could significantly
influence planetary atmospheric evolution. This work demonstrates the
power of X-ray surveys in constraining the high-energy environments of
exoplanets and underscores the critical role of stellar activity in
planetary habitability.
Description:
Parameters used in the paper for the derivation of luminosities used in
the analysis of habitability zones for theoretical earth-like planets
around eROSITA stellar sources.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 160 3750 Parameters used for the derivation of luminosities
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
J/A+A/682/A34 : SRG/eROSITA all-sky survey catalogs (eRASS1) (Merloni+, 2024)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- eRASSID ID of source in eRASS1
7- 16 F10.6 deg RAdeg Right ascension (J2000.0)
18- 29 F12.8 deg DEdeg Declination (J2000.0)
31- 42 F12.7 pc Dist The median of the geometric distance posterior
44- 53 F10.7 mag Gmag Mean magnitude in the G band
55- 70 F16.13 mag BP-RP BP-RP colour
72- 90 F19.15 mas plx Parallax
93-107 E15.10 mW/m2 F0.2-0.5 Unabsorbed flux in the 0.2-0.5keV energy range
obtained by fitting the eROSITA spectra with
a 2 Apec model (in erg/cm2/s)
109-123 E15.10 mW/m2 F0.2-1.0 Unabsorbed flux in the 0.5-1.0keV energy range
obtained by fitting the eROSITA spectra with
a 2 Apec model (in erg/cm2/s)
125-139 E15.10 mW/m2 F0.1-2.4 Unabsorbed flux in the 0.1-2.4keV energy range
obtained by fitting the eROSITA spectra with
a 2 Apec model (in erg/cm2/s)
141-150 F10.8 Msun MassFlame ? Mass of the star from FLAME
152-160 F9.4 K TeffMSC1 ? Effective temperature of the primary from
MSC using BP/RP spectra and parallax
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Acknowledgements:
Efrain Gatuzz, egatuzz(at)mpe.mpg.de
License: CC-BY-4.0
(End) Patricia Vannier [CDS] 13-May-2026