Measured Mass-Loss Rates of Solar-like Stars as a Function of Age and Activity

By B. Wood, H. Mueller, Gary Zank, J. Linsky. 2002

350 citations recorded by the source corpus.

Collisions between the winds of solar-like stars and the local interstellar medium result in a population of hot hydrogen gas surrounding these stars. Absorption from this hot H I can be detected in high-resolution Lyα spectra of these stars from the Hubble Space Telescope. The amount of absorption can be used as a diagnostic for the stellar mass-loss rate. We present new mass-loss rate measurements derived in this fashion for four stars (ϵ Eri, 61 Cyg A, 36 Oph AB, and 40 Eri A). Combining these measurements with others, we study how mass loss varies with stellar activity. We find that for the solar-like GK dwarfs, the mass loss per unit surface area is correlated with X-ray surface flux. Fitting a power law to this relation yields ∝ F. The active M dwarf Proxima Cen and the very active RS CVn system λ And appear to be inconsistent with this relation. Since activity is known to decrease with age, the above power-law relation for solar-like stars suggests that mass loss decreases with time. We infer a power-law relation of ∝ t-2.00±0.52. This suggests that the solar wind may have been as much as 1000 times more massive in the distant past, which may have had important ramifications for the history of planetary atmospheres in our solar system, that of Mars in particular.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/c1e6e4842b7178d5a60f62c494464ad836565aeb

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Citations in the corpus

• X-rays from solar system objects (2007, methodology): “g the Chandra X-ray Observatory (Wargelin and Drake, 2002). The null detection of a CX halo implied an upper limit to the mass–loss rate of 14 times the solar rate of 2 ×10 -14 solar masses per year. Wood et al. (2002) derived an upper limit for Prox Cen of 0.2 times the solar rate using H Ly α abso”
• Dust Dynamics, Surface Brightness Profiles, and Thermal Spectra of Debris Disks: The Case of AU Microscopii (2005, background): “Wood et al. (2002) and Wood et al. (2005) study the relationship between X-ray luminosity and stellar mass loss rate by measuring Ṁ∗ from a handful of M, K, and G dwarfs having ages & 500 Myr.”
• Mercury’s Weather-Beaten Surface: Understanding Mercury in the Context of Lunar and Asteroidal Space Weathering Studies (2014, background): “Under current ISM conditions interstellar hydrogen is entirely ionized within a few AU from the Sun; however, in Zank and Frisch’s (1999) simulation, the interstellar neutral hydrogen density at Earth changes from essentially zero to ∼2 cm−3, thus exposing Earth to bombardment by H0.”
• Young Stars Near the Sun (2004, background): “Measurements of ∼10 stars of solar mass suggest that massloss rates decline as a star ages (Gaidos et al. 2000, Wood et al. 2002).”
• Atmospheric Escape and Evolution of Terrestrial Planets and Satellites (2008, background): “However, the present stellar sample analyzed by Wood et al. (2002, 2005), Lundin et al. (2007) is not large enough; therefore, many uncertainties regarding the early solar wind remain, and more observations of young solar-like G and K stars are needed to enhance our knowledge of stellar winds…”
• The Cosmic Shoreline: The Evidence that Escape Determines which Planets Have Atmospheres, and what this May Mean for Proxima Centauri B (2017, background): “This can happen if other gases are scarce (Wordsworth and Pierrehumbert 2013), or the planet could enter a “moist greenhouse” state (Kasting 1988; Kasting et al. 2015; Leconte et al. 2013a; Wolf and Toon 2015).)”
• Stellar Lyα Emission Lines in the Hubble Space Telescope Archive: Intrinsic Line Fluxes and Absorption from the Heliosphere and Astrospheres (2005, methodology): “Mass loss rates have been measured for all of the older detections, and these measurements have been used to infer how winds vary with age and activity for solar-like main sequence stars (Wood et al. 2002b).”
• TESTING A PREDICTIVE THEORETICAL MODEL FOR THE MASS LOSS RATES OF COOL STARS (2011, background): “For binary systems with astrospheric measurements ofṀ (see, e.g., Wood et al. 2002), the numbers given are assumed to be the sum of both stars’ mass loss rates.”
• FORMATION AND EVOLUTION OF PLANETARY SYSTEMS: PROPERTIES OF DEBRIS DUST AROUND SOLAR-TYPE STARS (2008, background): “However, given the uncertainties on the scaling of mass loss rates with stellar age (Wood et al. 2002, 2005), we do not consider wind drag effects.”
• Stellar winds on the main-sequence - II. The evolution of rotation and winds (2015, background): “More important are the measurements of the mass loss rates of several solar analogues by Wood et al. (2002), Wood et al. (2005), and Wood et al. (2014).”
• Loss of water from Mars: Implications for the oxidation of the soil (2003, methodology): “Hubble Space Telescope high-resolution spectrosc observations of the H Lyman-α feature of several nearb main-sequence stars carried out by Wood et al. (2002) revealed neutral hydrogen absorption associated with th teraction between the stars’ fully ionized coronal winds w the partially ionized…”
• The Sun in Time: Activity and Environment (2007, methodology): “The only independent variable, the stellar age, then determines the rotation period and, through the internal magnetic dynamo, magnetic activity at all levels of the stellar atmosphere, probably including characteristics of the stellar wind (Wood et al., 2002, 2005; Kulikov et al., 2006).”