V_V ori

[Casper le fantôme]

Ce truc me retourne le cerveau et je ne trouve pas grand chose sur le sujet.

Définition étoile variable type orion éruptive.

[Casper le fantôme]

Ma première
V* V1515 Cyg
20 23 42.143 +42 12 28.19

https://aladin.cds.unistra.fr/AladinLit ... SS2%2Fblue

[Casper le fantôme]

Deuxième
Ben voilà comme d'habitude perdue grrrrrrr

[Casper le fantôme]

3 ème

V* SS Ori
05 33 32.099 -06 18 41.94

[pejive]

Il semble qu'il y ait diverses catégories de variables type Orion, principalement les types FU Ori et T Tauri
Attention V* V Ori est de type Mira (variable à longue période)

1. Eruptive Variable Stars

Eruptive variables are stars varying in brightness because of violent processes and flares occurring in their chromospheres
and coronae. The light changes are usually accompanied by shell events or mass outflow in the form of stellar winds of variable
intensity and/or by interaction with the surrounding interstellar medium. This class includes the following types:

FU Orion variables of the FU Orionis type. Characterized by
gradual increases in brightness by about 6 mag in several months,
followed by either almost complete constancy at maximum that is
sustained for long periods of time or slow decline by 1-2 mag.
Spectral types at maximum are in the range Ae(alpha) - Gpe(alpha).
After an outburst, a gradual development of an emission spectrum
is observed and the spectral type becomes later. These variables
probably mark one of the evolutionary stages of T Tauri-type Orion
variables (INT), as evidenced by an outburst of one member, V1057
Cyg, but its decline (2.5 mag in 11 years) commenced immediately
after maximum brightness was attained. All presently known FU Ori
variables are coupled with reflecting cometary nebulae.

GCAS Eruptive irregular variables of the Gamma Cas type. These
are rapidly rotating B III-IVe stars with mass outflow from their
equatorial zones. The formation of equatorial rings or disks is
often accompanied by temporary fading. Light amplitudes may reach
1.5 mag in V.

I Poorly studied irregular variables with unknown features of light
variations and spectral types. This is a very inhomogeneous group
of objects.

IA Poorly studied irregular variables of early (O-A) spectral type.

IB Poorly studied irregular variables of intermediate (F-G) to
late (K-M) spectral type.

IN Orion variables. Irregular, eruptive variables connected with
bright or dark diffuse nebulae or observed in the regions of these
nebulae. Some of them may show cyclic light variations caused by
axial rotation. In the Spectrum-Luminosity diagram, they are
found in the area of the main sequence and subgiants. They are
probably young objects that, during the course of further
evolution, will become light-constant stars on the zero-age main
sequence (ZAMS). The range of brightness variations may reach
several magnitudes. In the case of rapid light variations having
been observed (up to 1 mag in 1-10 days), the letter "S" is added
to the symbol for the type (INS). This type may be divided into
the following subtypes:

INA Orion variables of early spectral types (B-A or Ae). They are often
characterized by occasional abrupt Algol-like fadings (T Ori);

INB Orion variables of intermediate and late spectral types, F-M or
Fe-Me (BH Cep, AH Ori). F-type stars may show Algol-like fadings
similar to those of many INA stars; K-M stars may produce flares
along with irregular light variations;

INT,IT Orion variables of the T Tauri type. Stars are assigned to
this type on the basis of the following (purely spectroscopic)
criteria: spectral types are in the range Fe-Me. The spectra of
most typical stars resemble the spectrum of the solar
chromosphere. The feature specific to the type is the presence of
the flourescent emission lines Fe II 4046, 4132 A (anomalously
intense in the spectra of these stars), emission lines [Si II] and
[O I], as well as the absorption line Li I 6707 A. These variables
are usually observed only in diffuse nebulae. If it is not
apparent that the star is associated with a nebula, the letter "N"
in the symbol for the type may be omitted, e.g., IT (RW AUR);

IN(YY) Some Orion variables (YY Ori) show the presence of absorption
components on the redward sides of emission lines, indicating the
infall of matter toward the stars' surfaces. In such cases, the
symbol for the type may be accompanied by the symbol "YY".

IS Rapid irregular variables having no apparent connection with diffuse
nebulae and showing light changes of about 0.5 - 1.0 mag within
several hours or days. There is no strict boundary between rapid
irregular and Orion variables. If a rapid irregular star is
observed in the region of a diffuse nebula, it is considered an
Orion variable and designated by the symbol INS. To attribute
a variable to the IS type, it is necessary to take much care to be
certain that its light changes are really not periodic. Quite a
number of the stars assigned to this type in the third edition of
the GCVS turned out to be eclipsing binary systems, RR Lyrae
variables, and even extragalactic BL Lac objects.

ISA Rapid irregular variables of the early spectral types, B-A or Ae;

ISB Rapid irregular variables of the intermediate and late spectral
types, F-M and Fe-Me.

RCB Variables of the R Coronae Borealis type. These are hydrogen-poor,
carbon- and helium-rich, high-luminosity stars belonging to the
spectral types Bpe-R, which are simultaneously eruptive and
pulsating variables. They show slow nonperiodic fadings by 1-9
mag in V lasting from a month or more to several hundred days.
These changes are superposed on cyclic pulsations with amplitudes
up to several tenths of a magnitude and periods in the range
30-100 days.

RS Eruptive variables of the RS Canum Venaticorum type. This type is
ascribed to close binary systems with spectra showing Ca II H and
K in emission, their components having enhanced chromospheric
activity that causes quasi-periodic light variability. The period
of variation is close to the orbital one, and the variability
amplitude is usually as great as 0.2 mag in V (UX Ari). They are
X-ray sources and rotating variables. RS CVn itself is also an
eclipsing system (see below).

SDOR Variables of the S Doradus type. These are eruptive,
high-luminosity Bpec-Fpec stars showing irregular (sometimes
cyclic) light changes with amplitudes in the range 1-7 mag in V.
They belong to the brightest blue stars of their parent galaxies.
As a rule, these stars are connected with diffuse nebulae and
surrounded by expanding envelopes (P Cyg, Eta Car).

UV Eruptive variables of the UV Ceti type, these are K Ve-M Ve stars
sometimes displaying flare activity with amplitudes from
several tenths of a magnitude up to 6 mag in V. The amplitude is
considerably greater in the ultraviolet spectral region. Maximum
light is attained in several seconds or dozens of seconds after
the beginning of a flare; the star returns to its normal
brightness in several minutes or dozens of minutes.

UVN Flaring Orion variables of spectral types Ke-Me. These are
phenomenologically almost identical to UV Cet variables observed
in the solar neighborhood. In addition to being related to
nebulae, they are normally characterized by being of earlier
spectral type and greater luminosity, with slower development of
flares (V389 Ori). They are possibly a specific subgroup of INB
variables with irregular variations superimposed by flares.

WR Eruptive Wolf-Rayet variables. Stars with broad emission features
of He I and He II as well as C II-C IV, O II-O IV, and N III-N V.
They display irregular light changes with amplitudes up to 0.1 mag
in V, which are probably caused by physical processes, in
particular, by nonstable mass outflow from their atmospheres.

Edit casper pour complément
https://fr.m.wikipedia.org/wiki/%C3%89toile_variable

https://fr.m.wikipedia.org/wiki/%C3%89t ... FU_Orionis

https://fr.m.wikipedia.org/wiki/%C3%89t ... pe_T_Tauri
https://fr.m.wikipedia.org/wiki/%C3%89t ... _de_Herbig

Et enfin....... la boucle est bouclée en retombant sur les Herbig-Haro, incroyable parcours.

Merci @pejive je deviens de moins en moins débutant (ce n'est pas fait pour m'arranger ça mon éthique astro vient d'en prendre un coup

[Casper le fantôme]

Merci beaucoup @pejive en fait voilà regarde

C'est ça qui m'interpelle au plus haut point 》 avec "mes mots à moi" des étoiles ayant des "motifs géométriques" ...les éruptions très certainement ça me tortille les neurones rahhhhhhhhhhhhhh il m'en faut d'autres .

Voilà donc au cas où pensez au fantôme en cas de découverte de ces étoiles ultras intéressantes.........bien entendu pour publication pour la communauté

[pejive]

SDSS9 montre des nébulosités à cet endroit.

Em.jpg (92.17 Kio) Consulté 6085 fois

Em-HBC694.jpg (58.38 Kio) Consulté 6085 fois

[Casper le fantôme]

Tainnnnnnnnnn j'ai trouvé un truc.
Bon déjà ma 2eme ben c'était Parsamian 21 (bonjour ma mémoire)

Ensuite a force de cliquer partout.

https://simbad.cds.unistra.fr/mobile/ob ... 5C&max=101

101 v_v

Yes a depioter

Hop je rajoute
https://simbad.cds.unistra.fr/mobile/bi ... amian%2021
Et 2 croissants pour la route
Et hop
https://simbad.cds.unistra.fr/mobile/bi ... amian%2021
C'est Noël avant l'heure

[Casper le fantôme]

Très honnêtement aladin lite c'est que du bonheur

[Casper le fantôme]

Sacre bazar ce dossier mais y a tout pour débuter