The Formation of Chondrules at High Gas Pressures in the Solar Nebula

Galy, Αlbert; Young, Edward; Ash, R. D.; O’Nions, R.K.

doi:10.1126/science.290.5497.1751

Cited by 160 publications

(200 citation statements)

References 18 publications

Supporting

Mentioning

178

Contrasting

Order By: Relevance

“…There are also similar isotopic differences compared to the data set of Seitz et 324 al., 2007. 325 Bulk chondrite δ 26 Mg values range from -0.38 to -0.15‰ ( results from individual meteorites generally agree well with whole-rock results from 330 most other studies (Galy et al, 2000;Baker et al, 2005;Teng et al, 2007;Wiechert 331 and Halliday, 2007;Teng et al, 2010), but are resolvably heavier than the results from 332 Chakrabarti and Jacobsen (2010). 333…”

Section: Chondrite Analyses 313supporting

confidence: 76%

Variations of Li and Mg isotope ratios in bulk chondrites and mantle xenoliths

Strandmann

Elliott

Marschall

et al. 2011

Geochimica et Cosmochimica Acta

251

154

View full text Add to dashboard Cite

13We present whole rock Li and Mg isotope analyses of 33 ultramafic xenoliths from 14 the terrestrial mantle, which we compare with analyses of 30 (mostly chondritic) 15 meteorites. The accuracy of our new Mg isotope ratio measurement protocol is 16 substantiated by a combination of standard addition experiments, the absence of mass 17 independent effects in terrestrial samples and our obtaining identical values for rock 18 standards using 2 different separation chemistries and 3 different mass-spectrometric 19 introduction systems. Carbonaceous, ordinary and enstatite chondrites have 20

show abstract

Section: Chondrite Analyses 313supporting

confidence: 76%

Variations of Li and Mg isotope ratios in bulk chondrites and mantle xenoliths

Strandmann

Elliott

Marschall

et al. 2011

Geochimica et Cosmochimica Acta

251

154

View full text Add to dashboard Cite

show abstract

“…For this reason also, it is advantageous to evaporate the smaller grains first, because then oxides will be incorporated into the gas and the partial pressures of condensable elements will increase locally. This helps to make liquids stable at high temperature and also suppresses the evaporation of silicate liquids that would have caused heavy isotope enrichment of resulting chondrules; such enrichment is not observed (Galy et al 2000). Ebel & Grossman (2000) give a full treatment of what dust enrichments are necessary to make FeO-bearing silicates and to make chondrule liquids stable at low pressure relative to solids, as well as discussing dust enrichment scenarios with high oxygen fugacities.…”

Section: Resultsmentioning

confidence: 99%

Chondrule Formation and Protoplanetary Disk Heating by Current Sheets in Nonideal Magnetohydrodynamic Turbulence

Joung¹,

Low²,

Ebel³

2004

ApJ

View full text Add to dashboard Cite

We study magnetic field steepening due to ambipolar diffusion in protoplanetary disk environments and draw the following conclusions. Current sheets are generated in magnetically active regions of the disk where the ionization fraction is high enough for the magnetorotational instability to operate. In late stages of solar nebula evolution, the surface density is expected to decrease and dust grains are expected to gravitationally settle to the midplane. If the local dust-to-gas mass ratio near the midplane is increased above cosmic abundances by factors k10 3 , current sheets reach high enough temperatures to melt millimeter-sized dust grains and hence may provide the mechanism to form meteoritic chondrules. In addition, these current sheets possibly explain the near-infrared excesses observed in spectral energy distributions (SEDs) of young stellar objects. Direct imaging of protoplanetary disks via a nulling interferometer or, in the future, a multiband, adaptive optics coronagraph can test this hypothesis.

show abstract

“…They think that a significant amount of H 2 remains in the gas phase, but only a tiny fraction of this mass emits in the near-infrared. Nevertheless, Mg-isotopic abundances in chondrules suggest that high total gas pressure prevailed during chondrule formation, even if it was in a very localized environment (Galy et al 2000); to our best knowlegment it still has to be computed if such gas pressures are compatible with the pressure in the remaining disks around weak line T Tauri stars or in their flare eruptions.…”

Section: Effects Of Flares On Young Planetary Systemsmentioning

confidence: 99%

The weak-line T Tauri star V410 Tau

Fernández¹,

Stelzer

Henden

et al. 2004

A&A

View full text Add to dashboard Cite

Abstract. We show that V410 Tau, a weak-line T Tauri star, is a flaring star. This result comes from an intensive, coordinated monitoring campaign carried out in November 2001 at visible and X-ray wavelength ranges. It is confirmed by previous, isolated observations found in the literature. Flares tend to occur mainly around the star's minimum brightness, when the most active regions face us. We report on the strongest flare detected up to now on this star, for which we have obtained simultaneous visible Strömgren photometry and intermediate resolution spectroscopy. We derive decay times from 3 to 0.7 h at several wavelengths for the continuum in the 3600−5600 Å range. We estimate the energy involved in this and the other flares for which we have good time sampling, and conclude that the strongest event, at least, could have important consequences for the matter in the surroundings of the star. If similar events took place on the young Sun and lasted for several Myr, they could explain the anomalous abundances of elemental isotopes found in some meteorites. They could have also contributed to eliminate part of the primary atmospheres of the planet embryos and would have provided enough energy for the melting of solid iron-magnesium silicates, a process that may explain the presence of chondrules in chondritic meteorites. High resolution spectroscopy of the H α emission line in the quiescent states of V410 Tau enables us to study the variability of the broad component. We suggest that this component is related to microflaring activity, such as the one observed on more evolved, magnetically-active stars. The large velocities and the energy associated with this component support this hypothesis.

show abstract

The Formation of Chondrules at High Gas Pressures in the Solar Nebula

Cited by 160 publications

References 18 publications

Variations of Li and Mg isotope ratios in bulk chondrites and mantle xenoliths

Variations of Li and Mg isotope ratios in bulk chondrites and mantle xenoliths

Chondrule Formation and Protoplanetary Disk Heating by Current Sheets in Nonideal Magnetohydrodynamic Turbulence

The weak-line T Tauri star V410 Tau

Contact Info

Product

Resources

About