20:
869:
207:
BY Draconis variable. This type of variable is characterized by quasiperiodic photometric variations over time scales from less than a day to months, and amplitudes ranging from a few hundredths of a magnitude to 0.5
77:. The period is close to the star's mean rotational rate. The light curve is irregular over the duration of the period and it changes slightly in shape from one period to the next. For the star
335:
23:
163:
Lopez-Morales, Mercedes; Morrell, N. I.; Butler, R. P.; Seager, S. (2006), "Limits to
Transits of the Neptune-mass planet orbiting Gl 581",
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38:
726:
510:
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393:
381:
182:
656:
844:
817:
397:
116:. Ross 248 is the first discovered BY Draconis variable, the variability having been identified by
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592:
198:
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66:
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in 1950. The variability of BY Draconis itself was discovered in 1966 and studied in detail by
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249:
239:
89:
85:
744:
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220:
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19:
554:
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109:
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839:
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891:
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344:
105:
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42:
34:
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698:
561:
132:
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46:
45:. The name comes from the archetype for this category of variable star system,
683:
641:
128:
50:
718:
712:
143:, which are another class of variable stars that have active chromospheres.
135:
type. Likewise, the spectra of BY Draconis variables (particularly in their
177:
97:
93:
81:
the shape of the light curve over a period remained similar for a month.
58:
65:
activity. Resultant brightness fluctuations are generally less than 0.5
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18:
313:
693:
54:
317:
302:
Combined
General Catalog of Variable Stars (GCVS4.2, 2004 Ed.)
84:
Nearby K and M stars that are BY Draconis variables include
165:
26:
light curve of a BY Dra-type variable star V1297 Her
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634:
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573:
530:
523:
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427:
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244:, Cambridge astrophysics series, vol. 34,
238:Schrijver, Carolus J.; Zwaan, Cornelis (2000),
41:, usually K or M, and typically belong to the
329:
8:
223:; Richter, Gerold; Wenzel, Wolfgang (1984),
131:, resulting in additional variations of the
277:, Cambridge University Press, p. 374,
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16:Variable stars of late spectral types
7:
300:Samus N.N., Durlevich O.V., et al.
241:Solar and stellar magnetic activity
49:. They exhibit variations in their
14:
867:
127:Some of these stars may exhibit
1:
457:Blue large-amplitude pulsator
73:of BY Draconis variables are
271:; Jaschek, Mercedes (1990),
274:The Classification of Stars
124:over the period 1973–1976.
914:
246:Cambridge University Press
122:Pavel Fedorovich Chugainov
863:
506:Solar-like oscillations
447:Slowly pulsating B-type
53:due to rotation of the
583:Luminous blue variable
414:Rapidly oscillating Ap
27:
898:BY Draconis variables
31:BY Draconis variables
22:
771:Rotating ellipsoidal
679:AM Canum Venaticorum
626:RS Canum Venaticorum
225:Veränderliche Sterne
808:α Canum Venaticorum
308:The Brightest Stars
187:2006PASP..118.1506L
39:late spectral types
792:FK Comae Berenices
588:R Coronae Borealis
378:Classical cepheids
118:Gerald Edward Kron
28:
885:
884:
850:Planetary transit
826:
825:
747:
740:
721:
707:
689:Luminous red nova
665:
664:
647:Gamma Cassiopeiae
600:Yellow hypergiant
596:
564:
557:
519:
518:
405:
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221:Hoffmeister, Cuno
139:) are similar to
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621:FS Canis Majoris
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178:astro-ph/0609255
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874:Star portal
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855:W Ursae Majoris
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801:Magnetic fields
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616:Double periodic
609:Eruptive binary
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428:Blue-white with
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295:Further reading
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269:Jaschek, Carlos
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248:, p. 343,
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110:Epsilon Eridani
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738:Symbiotic nova
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652:Lambda Eridani
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485:Slow irregular
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345:Variable stars
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306:Schaaf, Fred,
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195:10.1086/508904
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90:Kapteyn's Star
86:Barnard's Star
35:variable stars
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780:Stellar spots
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764:Non-spherical
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501:Gamma Doradus
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452:PV Telescopii
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171:(849): 1506,
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137:H and K lines
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107:
106:Lalande 21185
103:
102:Lacaille 8760
99:
95:
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82:
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76:
75:quasiperiodic
72:
68:
64:
63:chromospheric
60:
57:coupled with
56:
52:
48:
44:
43:main sequence
40:
36:
32:
25:
21:
865:
786:
745:Z Andromedae
727:SW Sextantis
705:Intermediate
544:Herbig Ae/Be
419:SX Phoenicis
366:cepheid-like
307:
301:
273:
263:
240:
233:
224:
215:
206:
168:
164:
141:RS CVn stars
126:
114:Luyten 726-8
83:
71:Light curves
61:, and other
30:
29:
787:BY Draconis
671:Cataclysmic
576:supergiants
511:White dwarf
480:Semiregular
467:Long-period
442:Beta Cephei
437:Alpha Cygni
394:BL Herculis
382:Delta Scuti
79:BY Draconis
47:BY Draconis
845:Beta Lyrae
818:SX Arietis
684:Dwarf nova
657:Wolf–Rayet
574:Giants and
555:FU Orionis
398:W Virginis
227:, Springer
147:References
67:magnitudes
51:luminosity
832:Eclipsing
732:Symbiotic
719:Hypernova
713:Supernova
593:DY Persei
532:Protostar
353:Pulsating
59:starspots
892:Category
757:Rotating
524:Eruptive
409:RR Lyrae
402:RV Tauri
362:Cepheids
203:15156619
98:Ross 248
94:61 Cygni
562:T Tauri
389:Type II
183:Bibcode
133:UV Ceti
813:Pulsar
373:Type I
281:
252:
201:
129:flares
840:Algol
699:Polar
642:Flare
635:Other
549:Orion
494:Other
208:mags.
199:S2CID
173:arXiv
879:List
694:Nova
534:and
475:Mira
279:ISBN
250:ISBN
112:and
55:star
33:are
24:TESS
536:PMS
364:and
191:doi
169:118
37:of
894::
877:*
400:,
396:,
380:,
205:,
197:,
189:,
181:,
167:,
155:^
108:,
104:,
100:,
96:,
92:,
88:,
69:.
595:)
591:(
404:)
392:(
384:)
376:(
337:e
330:t
323:v
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185::
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Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
