31:
40:
34:
K line spectrum of KW 326, a dwarf star in the
Praesepe open cluster. The line is very wide and very deep, and it originates in the photosphere, just like any other absorption line. Several other lines are superimposed on it. In the center, the emission due to the K line itself, which takes place in
102:
The main interest of the Wilson–Bappu effect is in its use for determining the distance of stars too remote for direct measurements. It can be studied using nearby stars, for which independent distance measurements are possible, and it can be expressed in a simple analytical form. In other words,
253:
In 1977, Stencel published a spectroscopic survey that showed that the wing emission features seen in the broad wings of the K line among higher luminosity late type stars, share a correlation of line width and
327:
218:
231:
in distant stars is very challenging, requires long observations at big telescopes. Sometimes the emission feature in the core of the K line is affected by the
47:
is defined as the difference in wavelength between the points on either side of the emission at an average intensity between the K1 minimum and the K2 maximum
503:
247:
246:, and since the radiation at this wavelength does not reach the Earth's surface it can only be observed with satellites such as the
223:
The data error, however, is quite large: about 0.5 mag, rendering the effect too imprecise to significantly improve the
419:
Cassatella, A.; Altamore, A.; Badiali, M.; Cardini, D. (2001). "On the Wilson-Bappu relationship in the Mg II k line".
366:
421:
92:
88:
68:
162:
364:
Pace, G.; Pasquini, L.; Ortolani, S. (2003). "The Wilson-Bappu Effect, A tool to determine stellar distances".
99:
type M. The greater the emission band, the brighter the star, which is correlated with distance empirically.
71:
reported on the remarkable correlation between the measured width of the aforementioned emission line and the
242:
The Wilson–Bappu effect is also valid for the Mg II k line. However, the Mg II k line is at 2796.34 Å in the
232:
224:
127:
84:
281:
142:
479:
440:
385:
336:
290:
64:
456:
430:
401:
375:
318:
123:
119:
72:
277:"H and K Emission in Late-Type Stars: Dependence of Line Width on Luminosity and Related Topics"
122:
of a star. The distance of a star follows immediately from the knowledge of both absolute and
448:
444:
393:
389:
344:
298:
483:
340:
294:
52:
148:
According to the latest calibration, the relation between absolute visual magnitude (M
497:
56:
460:
405:
323:"The CaII-M_v Correlation (Wilson-Bappu Effect) Calibrated by HIPPARCOS Parallaxes"
60:
17:
452:
397:
118:
and the analytical form expressing the Wilson–Bappu effect, we can determine the
243:
134:
96:
137:
parallaxes was made in 1999 by
Wallerstein et al. A later work also used W
435:
380:
83:. The correlation is independent of spectral type and is applicable to
30:
133:
The first calibration of the Wilson–Bappu effect using distance from
104:
474:
Stencel, R. E. (2009). "The Wilson-Bappu Effect - 50 Years Later".
349:
322:
303:
276:
227:. Another limitation comes from the fact that the measurement of W
38:
29:
103:
the Wilson–Bappu effect can be calibrated with stars within 100
76:
39:
107:
from the Sun. The width of the emission core of the K line (
328:
165:
141:measurements on high-resolution spectra taken with
212:
114:) can be measured in distant stars, so, knowing W
130:of the star is either negligible or well known.
235:. In these cases an accurate measurement of W
8:
321:; Machado-Pelaez, L.; Gonzalez, G. (1999).
213:{\displaystyle M_{V}=33.2-18.0\log(W_{0})}
434:
379:
348:
302:
201:
170:
164:
156:, transformed in km/s, is the following:
267:
27:Correlation among statistics of a star
55:in cool stars is among the strongest
7:
258:similar to the Wilson–Bappu effect.
248:International Ultraviolet Explorer
25:
275:Wilson O.C.; Bappu, V. (1957).
152:) expressed in magnitudes and W
59:which originates in the star's
207:
194:
1:
367:Astronomy & Astrophysics
43:Zoom on the emission core. W
520:
453:10.1051/0004-6361:20010816
422:Astronomy and Astrophysics
398:10.1051/0004-6361:20030163
504:Astronomical spectroscopy
73:absolute visual magnitude
145:, but a smaller sample.
79:. This is known as the
445:2001A&A...374.1085C
390:2003A&A...401..997P
233:interstellar extinction
225:cosmic distance ladder
214:
128:interstellar reddening
85:stellar classification
48:
36:
476:ASP Conference Series
282:Astrophysical Journal
215:
42:
33:
163:
126:, provided that the
87:main sequence types
484:2009ASPC..412..251S
341:1999PASP..111..335W
295:1957ApJ...125..661W
81:Wilson–Bappu effect
18:Wilson-Bappu effect
210:
124:apparent magnitude
120:absolute magnitude
49:
37:
239:is not possible.
69:M. K. Vainu Bappu
35:the chromosphere.
16:(Redirected from
511:
488:
487:
471:
465:
464:
438:
436:astro-ph/0106070
429:(3): 1085–1091.
416:
410:
409:
383:
381:astro-ph/0301637
361:
355:
354:
352:
315:
309:
308:
306:
272:
219:
217:
216:
211:
206:
205:
175:
174:
113:
21:
519:
518:
514:
513:
512:
510:
509:
508:
494:
493:
492:
491:
473:
472:
468:
418:
417:
413:
374:(3): 997–1008.
363:
362:
358:
319:Wallerstein, G.
317:
316:
312:
274:
273:
269:
264:
257:
238:
230:
197:
166:
161:
160:
155:
151:
140:
117:
112:
108:
46:
28:
23:
22:
15:
12:
11:
5:
517:
515:
507:
506:
496:
495:
490:
489:
466:
411:
356:
350:10.1086/316332
310:
304:10.1086/146339
266:
265:
263:
260:
255:
236:
228:
221:
220:
209:
204:
200:
196:
193:
190:
187:
184:
181:
178:
173:
169:
153:
149:
138:
115:
110:
65:Olin C. Wilson
57:emission lines
44:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
516:
505:
502:
501:
499:
485:
481:
477:
470:
467:
462:
458:
454:
450:
446:
442:
437:
432:
428:
424:
423:
415:
412:
407:
403:
399:
395:
391:
387:
382:
377:
373:
369:
368:
360:
357:
351:
346:
342:
338:
334:
330:
329:
324:
320:
314:
311:
305:
300:
296:
292:
288:
284:
283:
278:
271:
268:
261:
259:
251:
249:
245:
240:
234:
226:
202:
198:
191:
188:
185:
182:
179:
176:
171:
167:
159:
158:
157:
146:
144:
136:
131:
129:
125:
121:
106:
100:
98:
94:
90:
86:
82:
78:
74:
70:
66:
62:
58:
54:
41:
32:
19:
475:
469:
426:
420:
414:
371:
365:
359:
335:(757): 335.
332:
326:
313:
286:
280:
270:
252:
241:
222:
147:
132:
101:
80:
63:. In 1957,
61:chromosphere
53:Ca II K line
50:
244:ultraviolet
262:References
192:
183:−
135:Hipparcos
97:Red giant
498:Category
461:16286422
406:17029463
480:Bibcode
478:: 251.
441:Bibcode
386:Bibcode
337:Bibcode
291:Bibcode
289:: 661.
105:parsecs
75:of the
459:
404:
95:, and
457:S2CID
431:arXiv
402:S2CID
376:arXiv
186:18.0
180:33.2
77:star
67:and
51:The
449:doi
427:374
394:doi
372:401
345:doi
333:111
299:doi
287:125
189:log
143:CCD
500::
455:.
447:.
439:.
425:.
400:.
392:.
384:.
370:.
343:.
331:.
325:.
297:.
285:.
279:.
250:.
91:,
486:.
482::
463:.
451::
443::
433::
408:.
396::
388::
378::
353:.
347::
339::
307:.
301::
293::
256:v
254:M
237:0
229:0
208:)
203:0
199:W
195:(
177:=
172:V
168:M
154:0
150:v
139:0
116:0
111:0
109:W
93:K
89:G
45:0
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
