Tiny star's violent outburst catches astronomers' attention — years late

rod

Oct 22, 2019
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Just like any small child, a tiny star had a huge yet unexpected temper tantrum.

Tiny star's violent outburst catches astronomers' attention — years late : Read more
"A number of similar stars had been seen to emit super flares in the optical part of the spectrum, but this is the first unambiguous detection of such an eruption at X-ray wavelengths," ESA added in the same statement."

I did some more study on this L dwarf super-flare report. The star is apparently about 0.08 solar masses and some 240 pc distance from Earth. The attached PDF report from ArXiv.org states "Time-domain astronomy has uncovered a new class of stellar ‘superflares’ with bolometric energies higher than 10^33 erg (Maehara et al. 2012), events that significantly influence planetary habitability (Armstrong et al. 2016; Lingam & Loeb 2017) and may have been imprinted on meteoritic chemical abundances in our own solar system (Mishra & Marhas 2019)...These bursts are comparable to the strongest flares in FGKM stars, and are remarkable given that most tracers of quiescent magnetic emission (H alpha and X-ray) decline in the L dwarf sequence (Schmidt et al. 2015; Stelzer et al. 2006a).", ref - EXTraS discovery of an X-ray superflare from an L dwarf

It seems spectral class MKGF stars can have very energetic flares, now L dwarfs too. This does impact the habitability of such stars to support livable exoplanets. We live on the Earth with a very stable Sun compared to many stars being uncovered in astronomy today. The L dwarf in this report, if it has a 1 day rotation period could spin some 4.56 km/s or faster vs. the Sun 2 km/s. Other stars that emit very energetic flares commonly spin fast too. Something to ponder in the grand design of the universe and how the Earth is very habitable today with an abundance of life.
 
Feb 24, 2020
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Zy Zhen, Junxian Wang, and Keely and S.L. Finkelstein, who published their analysis in 2010 as “X-ray Properties of the z ~ 4.5 Lyα Emitters in the Chandra Deep Field South Region” The Astrophysical Journal 718(1):52, report an object of this designation is a quasar. Is this a misidentification?
 
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rod

Oct 22, 2019
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Zy Zhen, Junxian Wang, and Keely and S.L. Finkelstein, who published their analysis in 2010 as “X-ray Properties of the z ~ 4.5 Lyα Emitters in the Chandra Deep Field South Region” The Astrophysical Journal 718(1):52, report an object of this designation is a quasar. Is this a misidentification?
It does not seem to be a misidentification. Here is something from the Abstract, "ABSTRACT We present the first detection of an X-ray flare from an ultracool dwarf of spectral class L. The event was identified in the EXTraS database of XMM-Newton variable sources, and its optical counterpart, J0331-27, was found through a cross-match with the Dark Energy Survey Year 3 release. Next to an earlier four-photon detection of Kelu-1, J0331-27 is only the second L dwarf detected in
X-rays, and much more distant than other ultracool dwarfs with X-ray detections (photometric distance of 240 pc). From an optical spectrum with the VIMOS instrument at the VLT, we determine the spectral type of J0331-27 to be L1. The X-ray flare has an energy of EX;F ~ 2 x 10^33 erg, placing it in the regime of superflares.", https://ui.adsabs.harvard.edu/abs/2020arXiv200208078D/abstract

The spectrum shows it is an L dwarf star determined to be about 0.08 solar mass and 240 pc distance or about 783 light-years distance. The QSO you mention, z is 4.5. The cosmology calculators show this object is 12.369E+9 light-years look back time from Earth but comoving radial distance of nearly 25E+9 light-years distance using the cosmological redshift interpretation based upon the Big Bang expansion model. http://www.astro.ucla.edu/~wright/CosmoCalc.html

An L dwarf star spectrum is not a QSO and the L dwarf is much closer to the solar system, based upon the published metrics.
 

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