2004A&A...416..713G


C.D.S. - SIMBAD4 rel 1.7 - 2021.03.08CET02:42:57

2004A&A...416..713G - Astronomy and Astrophysics, volume 416, 713-732 (2004/3-3)

Flares from small to large: X-ray spectroscopy of Proxima Centauri with XMM-Newton.

GUEDEL M., AUDARD M., REALE F., SKINNER S.L. and LINSKY J.L.

Abstract (from CDS):

We report results from a comprehensive study of the nearby M dwarf Proxima Centauri with the XMM-Newton satellite, using simultaneously its X-ray detectors and the Optical Monitor with its U band filter. We find strongly variable coronal X-ray emission, with flares ranging over a factor of 100 in peak flux. The low-level emission is found to be continuously variable on at least three time scales (a slow decay of several hours, modulation on a time scale of 1 hr, and weak flares with time scales of a few minutes). Several weak flares are characteristically preceded by an optical burst, compatible with predictions from standard solar flare models. We propose that the U band bursts are proxies for the elusive stellar non-thermal hard X-ray bursts suggested from solar observations. In the course of the observation, a very large X-ray flare started and was observed essentially in its entirety. Its peak luminosity reached 3.9x1028erg/s [0.15-10 keV], and the total X-ray energy released in the same band is derived to be 1.5x1032ergs. This flare has for the first time allowed to measure significant density variations across several phases of the flare from X-ray spectroscopy of the OVII He-like triplet; we find peak densities reaching up to 4x1011cm–3 for plasma of about 1-5MK. Abundance ratios show little variability in time, with a tendency of elements with a high first ionization potential to be overabundant relative to solar photospheric values. Using FeXVII lines with different oscillator strengths, we do not find significant effects due to opacity during the flare, indicating that large opacity increases are not the rule even in extreme flares. We model the large flare in terms of an analytic 2-Ribbon flare model and find that the flaring loop system should have large characteristic sizes (≃1R*) within the framework of this simplistic model. These results are supported by full hydrodynamic simulations. Comparing the large flare to flares of similar size occurring much more frequently on more active stars, we propose that the X-ray properties of active stars are a consequence of superimposed flares such as the example analyzed in this paper. Since larger flares produce hotter plasma, such a model also explains why, during episodes of low-level emission, more active stars show hotter plasma than less active stars.

Abstract Copyright:

Journal keyword(s): stars: activity - stars: coronae - stars: individual: Proxima Centauri - X-rays: stars

Simbad objects: 1

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Number of rows : 1

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 NAME Proxima Centauri Er* 14 29 42.9451234609 -62 40 46.170818907 14.21 12.95 11.13 9.45 7.41 M5.5Ve 1018 0

    Equat.    Gal    SGal    Ecl

C.D.S. - SIMBAD4 rel 1.7 - 2021.03.08CET02:42:57

Available data : Basic data  •  Identifiers  •  Plot & images  •  Bibliography  •  Measurements  •  External archives  •  Notes  •  Annotations


Basic data :
NAME Proxima Centauri -- Eruptive variable Star
Origin of the objects types :

(Ref) Object type as listed in the reference "Ref"
(acronym) Object type linked to the acronym according to the original reference
() Anterior to 2007, before we can link the objet type to a reference, or given by the CDS team in some particular cases

Other object types:
* (2014AJ,GJ,...), PM* (2016ApJ,Ci,...), X (1E,2E,...), UV (2016ApJ,2EUVE,...), IR (IRAS,2MASS,...), ** (CCDM,WDS), Er* (2017ARep,[GKL99]), V* (CSV,V*), Ro* (2012A&A)
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
ICRS coord. (ep=J2000) :
14 29 42.9451234609 -62 40 46.170818907 (Optical) [ 0.0577 0.1050 90 ] A 2018yCat.1345....0G
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
FK4 coord. (ep=B1950 eq=1950) :
14 26 18.9987217508 -62 28 04.393715964 [ 0.0577 0.1050 90 ]
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
Gal coord. (ep=J2000) :
313.9398596229609 -01.9271500019602 [ 0.0577 0.1050 90 ]
Syntax of proper motions is : "pm-ra pm-dec [error ellipse] quality bibcode"
  • pm-ra : mu-ra*cos(dec) (expressed in the ICRS system in mas/yr)
  • pm-dec : mu-dec (expressed in the ICRS system in mas/yr)
  • [error ellipse] : error major axis and minor axis (in mas), orientation angle (in deg)
  • quality : flag of quality (A=best quality -> E=worst quality, {� } =unknown quality)
  • bibcode : bibcode of the proper motion reference
Proper motions mas/yr :
-3781.306 769.766 [0.085 0.189 90] A 2018yCat.1345....0G
Syntax of radial velocity (or/and redshift) is : "value [error] (wavelength) quality bibcode"
  • value : radial velocity or/and redshift (Heliocentric frame) according to your Output Options
    (redshift may be not displayed if the data value is <0 and the database inside value is a radial velocity)
  • [error] : error of the corresponding value displayed before
  • (wavelength) : wavelength range of the measurement : Rad, mm, IR, Opt, UV, Xray, Gam or  '∼'(unknown)
  • quality : flag of quality ( A=best quality -> E=worst quality, {� } =unknown quality)
  • bibcode : bibcode of the value's origin
Radial velocity / Redshift / cz :
V(km/s) -22.40 [0.5] / z(~) -0.000075 [0.000002] / cz -22.40 [0.50]
   A 2006A&A...460..695T
Syntax of parallax is : 'value quality [error] bibcode'
  • value : parallax value
  • quality : flag of quality (A=best quality -> E=worst quality, {� } =unknown quality)
  • [error] : mean error
  • bibcode : bibcode of the parallax reference
Parallaxes (mas):
768.5004 [0.2030] A 2018yCat.1345....0G
Spectral type is made of 3 parts: %coding is composed of 4 parts :
  • the spectral type, which is made of a temperature class, eventually a luminosity class (roman number) and/or spectral peculiarities;
  • a quality letter: A=best quality→E=worst quality, {� } =unknown quality %
  • a quality letter: A=best quality -> E=worst quality, {� } =unknown quality
  • bibcode : bibcode of the spectral type reference
Spectral type:
M5.5Ve C 1991AJ....101..662B
Syntax of fluxes (or magnitudes) is : "filter-name (System) flux-value [error] quality MultVarFlags bibcode"
  • filter-name : U, B, V, R, I, G, J, H, K, u, g, r, i, z
  • (System) : may be AB (default is Vega)
  • flux-value : value of flux or magnitude
  • [error] : error value
  • quality : flag of quality of the flux value ( A=best quality -> E=worst quality, {� } =unknown quality)
  • MultVarFlags : Mult is zero or one char (J) for joined photometry ; Var can be zero or two chars (V[0-4])
  • bibcode : bibcode of the flux reference
Fluxes (9) :
U 14.21 [~] D 2014AJ....147...21J
B 12.95 [~] D 2014AJ....147...21J
V 11.13 [~] D 2014AJ....147...21J
R 9.45 [~] D 2014AJ....147...21J
G 8.9536 [0.0009] C 2018yCat.1345....0G
I 7.41 [~] D 2014AJ....147...21J
J 5.357 [0.023] C 2003yCat.2246....0C
H 4.835 [0.057] C 2003yCat.2246....0C
K 4.384 [0.033] C 2003yCat.2246....0C
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Suggestions are: crowded field: 0.5 to 1.5 arcsec, 3 arcsec otherwise; uncertain coordinates (SIMBAD quality E or coordinates without reference): 5 to 30 arsec (risky!).

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Identifiers (52) :
An access of full data is available using the icon Vizier near the identifier of the catalogue

GJ 551 GALEX 6387417244251458613 2MASS J14294291-6240465 RE J142950-624056
* alf Cen C GEN# +6.10010551 NAME Proxima Cen RX J1429.7-6240
CCDM J14396-6050C GEN# +6.00105721 NAME Proxima 1RXS J142947.9-624058
Ci 20 861 HIC 70890 NAME Proxima Centauri TIC 388857263
CSI-62-14263 HIP 70890 NLTT 37460 V* V645 Cen
CSV 2142 IRAS 14260-6227 PLX 3278 WDS J14396-6050C
1E 1425.9-6228 JP11 5156 PLX 3278.00 WISEA J142937.35-624038.3
2E 1426.0-6227 JP11 5155 PM 14263-6228 Zkh 211
2E 3278 JP11 5187 PM J14297-6240 [AOP94] 6
1ES 1426-62.4 LFT 1110 PMSC 14328-6025C [FS2003] 0708
2EUVE J1429-62.6 LHS 49 2RE J142946-624031 [GKL99] 301
EUVE J1429-62.6 LPM 526 2RE J1429-624 [RHG95] 2291
EUVE J1430-62.6 LTT 5721 RE J1429-624 Gaia DR2 5853498713160606720

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References (1018 between 1850 and 2021) (Total 1018)
Simbad bibliographic survey began in 1850 for stars (at least bright stars) and in 1983 for all other objects (outside the solar system).
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Collections of Measurements


distance : 1    velocities : 2    ROT : 1    PM : 8    Fe_H : 3    PLX : 5    MK : 9    V* : 2   

   

Observing logs


XMM : 2    IUE : 47   

   


External archives :

Archive data at HEASARC - High-Energy Astrophysics Science Archive Research Center

Data at NED - NASA/IPAC Extragalactic Database : NAME Proxima Centauri

Link by name to the catalogue in VizieR :

GJ 551 CCDM J14396-6050C 2E 3278 EUVE J1429-62.6 EUVE J1430-62.6
HIC 70890 HIP 70890 IRAS 14260-6227 LHS 49 2MASS J14294291-6240465
NLTT 37460 PLX 3278 2RE J142946-624031 2RE J1429-624 1RXS J142947.9-624058
V* V645 Cen WDS J14396-6050C WISEA J142937.35-624038.3 [GKL99] 301 Gaia DR2 5853498713160606720

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2021.03.08-02:42:57

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