منكب الجوزاء

(تم التحويل من Betelgeuse)

كوكبة الجوزاء
Betelgeuse (α Ori)
Position Alpha Ori.png
The pink arrow at the star on left labeled α indicates Betelgeuse in Orion.
بيانات الرصـد
الحقبة J2000.0      اعتدال J2000.0
الكوكبة الجبار
الصعود المستقيم 05h 55m 10.3053s[1]
الميل +07° 24′ 25.426″[1]
القدر الظاهري (V)0.42[1] (0.3 to 1.2)
الخـصـائص
النوع الطيفيM2Iab[1]
U-B دليل الألوان2.06[2]
B-V دليل الألوان1.85[2]
النوع المتغيرSR c (Semi-Regular)[1]
علم القياسات الفلكية
السرعة القطرية (Rv)+21.91[1] كم/ث
الحركة الحقيقية (μ) RA: 24.95 ± 0.08[3] mas/yr
Dec.: 9.56 ± 0.15[3] mas/س
اختلاف المنظر (π)5.07 ± 1.10[3] mas
المسافة643 ± 146 [3] س ض
(197 ± 45 [3] ف ن)
القدر المطلق (MV)−6.05[4]
التـفـاصـيل
الكتلة~18–19[5] M
نصف القطر~1,180[6] R
جاذبية السطح (log g)-0.5[7]
الضياء~140,000[8] L
درجة الحرارة3,500[7][9] ك
المعدنية0.05 Fe/H[10]
الدوران5 km/s[9]
العمر~1.0×107 [5] سنة
تسميات أخرى
Betelgeuse, α Ori, 58 Ori, HR 2061, BD +7° 1055, HD 39801, FK5 224, HIP 27989, SAO 113271, GC 7451, CCDM J05552+0724AP, AAVSO 0549+07
مراجع قواعد البيانات
SIMBADdata

الإحداثيات: خريطة السماء 05س 55ق 10.3053ث, +07° 24′ 25.426″

منكب الجوزاء كما صورها مرصد هابل الفضائي

منكب الجوزاء بالإنگليزية: Alpha Orionis أو Betelgeuse نجم متغير غير منتظم هو ثاني أكثر النجوم لمعانًا في كوكبة الجبار، وتاسع أكثر النجوم لمعانًا في السماء. يعتبر نجم منكب الجوزاء عملاقًا أحمر. ويرجع السبب في شدة احمرار لونه إلى الانخفاض الشديد في درجة حرارته السطحية التي تعادل نصف درجة حرارة الشمس. غير أن حجم منكب الجوزاء يفوق حجم الشمس بحوالي 460 ضعفًا. وهو يبعد عن الأرض مسافة 430 سنة ضوئية تقريبًا، أي ما يعادل 130 فرسخ نجمي تقريبًا.

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التاريخ

الانفجار المترقب لمنكب الجوزاء في نهاية 2011.


الاكتشاف

Portrait of Sir John Herschel by Julia Margaret Cameron a few years before his death.


AAVSO V-band light curve of Betelgeuse (Alpha Orionis) from Dec. 1988 – Aug. 2002


الرؤية

The location of Betelgeuse near the famous "Belt of Orion".


ملف:GAIA Cam01 2.tif
Artist rendering of the upcoming Gaia mission with its expected launch in 2012.


Ultraviolet image of Betelgeuse showing the star's asymmetrical pulsations, expansion and contraction.
An illustration of the structure of the Sun showing photospheric granules :
1. Core
2. Radiative zone
3. Convective zone
4. Photosphere
5. Chromosphere
6. Corona
7. Sunspot
8. Granules
9. Prominence


Article Year1 Telescope # Spectrum λ (μm) (mas)2 Radii3 @
197±45 pc
Notes
Michelson 1920 Mt-Wilson 1 Visible 0.575 47.0 ± 4.7 3.2 - 6.3 AU Limb darkened +17% = 55.0
Bonneau 1972 Palomar 8 Visible 0.422-0.719 52.0 - 69.0 3.6 - 9.2 AU Strong correlation of with λ
Balega 1978 ESO 3 Visible 0.405-0.715 45.0 - 67.0 3.1 - 8.6 AU No correlation of with λ
1979 SAO 4 Visible 0.575-0.773 50.0 - 62.0 3.5 - 8.0 AU
Buscher 1989 WHT 4 Visible 0.633-0.710 54.0 - 61.0 4.0 - 7.9 AU Discovered asymmetries/hotspots
Wilson 1991 WHT 4 Visible 0.546-0.710 49.0 - 57.0 3.5 - 7.1 AU Confirmation of hotspots
Tuthill 1993 WHT 8 Visible 0.633-0.710 43.5 - 54.2 3.2 - 7.0 AU Study of hotspots on 3 stars
1992 WHT 1 NIR 0.902 42.6 ± 0:03 3.0 - 5.6 AU
Weiner 1999 ISI 2 MIR (N Band) 11.150 54.7 ± 0.3 4.1 - 6.7 AU Limb darkened = 55.2 ± 0.5
Perrin 1997 IOTA 7 NIR (K Band) 2.200 43.33 ± 0.04 3.3 - 5.2 AU K&L Band,11.5μm data contrast
Haubois 2005 IOTA 6 NIR (H Band) 1.650 44.28 ± 0.15 3.4 - 5.4 AU Rosseland diameter 45.03 ± 0.12
Hernandez 2006 VLTI 2 NIR (K Band) 2.099-2.198 42:57 ± 0:02 3.2 - 5.2 AU High precision AMBER results.
Ohnaka 2008 VLTI 3 NIR (K Band) 2.280-2.310 43.19 ± 0.03 3.3 - 5.2 AU Limb darkened 43.56 ± 0.06
Townes 1993 ISI 17 MIR (N Band) 11.150 56.00 ± 1.00 4.2 - 6.8 AU Systematic study involving 17 measurements at the same wavelength from 1993-2009
2008 ISI MIR (N Band) 11.150 47.00 ± 2.00 3.6 - 5.7 AU
2009 ISI MIR (N Band) 11.150 48.00 ± 1.00 3.6 - 5.8 AU
Harper 2004 VLA Also noteworthy, Harper et al in the conclusion of their paper make the following remark: "In a sense, the derived distance of 200 pc is a balance between the 131 pc (425 ly) Hipparcos distance and the radio which tends towards 250 pc (815 ly)"—hence establishing ± 815 ly as the outside distance for the star.

1The final year of observations, unless otherwise noted. 2Uniform disk measurement, unless otherwise noted. 3Radii calculations use the same methodology as outlined in Note #2 below Limb darkened measurement.

</ref> Using the Solar System as a yardstick, the orbit of Mars is about 1.5 AU, Ceres in the asteroid belt 2.7 AU, Jupiter 5.5 AU—consequently a photosphere which, depending on Betelgeuse's actual distance from Earth, could well extend beyond the Jovian orbit but not quite as far as Saturn at 9.5 AU.

Radio image showing the size of Betelgeuse's photosphere (circle) and the effect of convective forces on the star's asymmetric atmosphere as it expands beyond the orbit of Saturn.


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الخصائص

Hertzsprung–Russell diagram identifying supergiants like Betelgeuse that have moved off the main sequence.

الحركة

Orion OB1 Association


الكثافة

Sirius (Panel 4) is the brightest star in the night sky, but is tiny compared to Betelgeuse (Panel 5). Both Sirius and Betelgeuse traverse the sky the same time of year.

</ref>

Bowl volume of Wembley Stadium. The center circle (9.15 m radius) is a close analogy for the Earth's orbit around the Sun, while the air in the stadium is actually far more dense than the star itself.


Circumstellar dynamics

Interior view of one of the four 8.2-metre Unit Telescopes at ESO's VLT.


الاقتراب من المستعر الأعظم

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النظام النجمي

انظر أيضا

الهوامش


المصادر

  1. ^ أ ب ت ث ج ح "SIMBAD query result: BETELGEUSE – Semi-regular pulsating Star". Centre de Données astronomiques de Strasbourg. Retrieved 2007-06-20.
  2. ^ أ ب Nicolet, B. (1978). "Catalogue of homogeneous data in the UBV photoelectric photometric system" (PDF). Astronomy and Astrophysics. 34: 1–49. Bibcode:1978A&AS...34....1N. doi:A&AA ID. AAA022.002.025 Check |doi= value (help). Retrieved 2010-05-11.
  3. ^ أ ب ت ث ج Harper, Graham M.; Brown, Alexander; Guinan, Edward F. (2008). "A New VLA-Hipparcos Distance to Betelgeuse and its Implications" (PDF). The Astronomical Journal. 135 (4): 1430–40. Bibcode:2008AJ....135.1430H. doi:10.1088/0004-6256/135/4/1430. Retrieved 2010-07-10. Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  4. ^ Note: Absolute magnitude calculations can vary significantly depending on the assumed parallax measurements. An absolute magnitude of −6.05 assumes the SIMBAD recorded average apparent magnitude for Betelgeuse of 0.42 and the most recent distance estimates of 197 parsecs. Given a variability of 0.2 – 1.2, the absolute magnitude can be said to vary between – 6.27 to −5.27
  5. ^ أ ب Kaler, James B. (Jim). "Betelgeuse (Alpha Orionis)". Stars website. University of Illinois. Retrieved 2009-07-19.
  6. ^ See Note #2 for calculations
  7. ^ أ ب Lobel, Alex; Dupree, Andrea K. (2000, December). "Modeling the Variable Chromosphere of α Orionis" (PDF). The Astrophysical Journal,. 545 (1): 454–74. Bibcode:2000ApJ...545..454L. doi:10.1086/317784. Retrieved 2010-07-10. Check date values in: |year= (help)CS1 maint: extra punctuation (link) CS1 maint: multiple names: authors list (link)
  8. ^ A luminosity of 140,000 Suns is an imputed figure based on various considerations. Two of the most important variables that influence luminosity calculations are distance (See Enigmatic parallax) and angular separation (See Angular anomalies). The calculations can be seen in Note #4 with added discussion found at the Luminosity section on the discussion page.
  9. ^ أ ب Kervella, P.; Verhoelst, T.; Ridgway, S. T.; Perrin, G.; et al. (2009). "The close circumstellar environment of Betelgeuse. Adaptive optics spectro-imaging in the near-IR with VLT/NACO". Astronomy and Astrophysics. 504 (1): 115–25. Bibcode:2009A&A...504..115K. doi:10.1051/0004-6361/200912521. Retrieved 2010-07-10. Unknown parameter |month= ignored (help); Explicit use of et al. in: |author= (help)CS1 maint: multiple names: authors list (link)
  10. ^ Ramírez, Solange V.; Sellgren, K.; Carr, John S.; Balachandran, Suchitra C.; et al. (2000, July). "Stellar Iron Abundances at the Galactic Center" (PDF). The Astrophysical Journal,. 537 (1): 205–20. Bibcode:2000ApJ...537..205R. doi:10.1086/309022. Retrieved 2010-07-09. Explicit use of et al. in: |author= (help); Check date values in: |year= (help)CS1 maint: extra punctuation (link) CS1 maint: multiple names: authors list (link)

وصلات خارجية

  1. Orion: Head to Toe The molecular clouds which gave birth to Betelgeuse.
  2. Mars and Orion Over Monument Valley Stunning skyscape showing the relative brightness of Betelgeuse and Rigel.
  3. Frosted Leaf Orion Orion, the hunter, in its mythological pursuit of the Pleiades over Japan.
  4. The Spotty Surface of Betelgeuse A reconstructed image showing two hotspots, possibly convection cells.
  5. Simulated Supergiant Star Freytag's "Star in a Box" illustrating the nature of Betelgeuse's "monster granules".
  6. Why Stars Twinkle Image of Betelgeuse showing the effect of atmospheric twinkling in a microscope.
  7. Canaries Sky The glowing nebulas surrounding Betelgeuse.

قالب:Stars of Orion