IOAA 2013, Теория, кратки задачи — Задача 6
7th International Olympiad on Astronomy & Astrophysics — Theoretical Exam - Short Questions
Table of Constants
| Group | Quantity | Value |
|---|---|---|
| Earth | Mass () | kg |
| Earth | Radius () | m |
| Earth | Acceleration of gravity | 9.8 m/s² |
| Earth | Obliquity of Ecliptic | |
| Earth | Length of Tropical Year | 365.2422 mean solar days |
| Earth | Length of Sidereal Year | 365.2564 mean solar days |
| Earth | Albedo () | 0.39 |
| Moon | Mass | kg |
| Moon | Radius | m |
| Moon | Mean distance from Earth | m |
| Moon | Orbital inclination with the Ecliptic | |
| Moon | Albedo | 0.14 |
| Moon | Apparent magnitude (mean full moon) | −12.74 |
| Sun | Mass () | kg |
| Sun | Luminosity () | W |
| Sun | Absolute Magnitude () | 4.72 mag |
| Sun | Angular diameter | 0.5 degrees |
| Sun | Effective Surface Temperature | 5800 K |
| Jupiter | Jupiter’s orbit semi-major axis | 5.204 AU |
| Jupiter | Jupiter’s orbital period | 11.8618 yr |
| Distances and sizes | Diameter of human pupil | 6 mm |
| Distances and sizes | 1 AU | m |
| Distances and sizes | 1 pc | 206,265 AU |
| Distances and sizes | Distance from Sun to Barnard’s Star | 1.83 pc |
| Distances and sizes | Mars orbit semi-major axis | 1.52 AU |
| Physical constants | Gravitational constant () | N·m²·kg⁻² |
| Physical constants | Planck constant () | J·s |
| Physical constants | Boltzmann constant () | J·K⁻² |
| Physical constants | Stefan-Boltzmann constant () | W·m⁻²·K⁻⁴ |
| Physical constants | Hubble constant () | 72 km s⁻¹ Mpc⁻¹ |
| Physical constants | Speed of light () | 299,792,458 m/s |
| Physical constants | Proton mass | 938.27 MeV·c⁻² |
| Physical constants | Deuterium mass | 1875.60 MeV·c⁻² |
| Physical constants | Neutron mass | 939.56 MeV·c⁻² |
| Physical constants | Helium-3 mass | 2808.30 MeV·c⁻² |
| Physical constants | Helium-4 mass | 3727.40 MeV·c⁻² |
The brightest stars visible from Greece
| Star | Designation | α (2000), h m | δ (2000), ° ′ | m(V), mag | M(V), mag | B−V | Spectral Type |
|---|---|---|---|---|---|---|---|
| Alpheratz | α And | 00 08 | +29 05 | 2.03 | ‒0.9 | ‒0.10 | A0 p |
| Caph | β Cas | 00 09 | +59 09 | 2.26 | +1.5 | +0.34 | F2 IV |
| Schedar | α Cas | 00 40 | +21 26 | 2.22 | ‒1.0 | +1.17 | K0 II |
| Diphda | β Cet | 00 44 | ‒17 59 | 2.04 | +0.2 | +1.04 | K0 III |
| Mirach | β And | 01 10 | +35 37 | 2.06 | ‒0.4 | +1.62 | M0 III |
| Achernar | α Eri | 01 38 | ‒57 15 | 0.48 | ‒1.6 | ‒0.18 | B5 IV |
| Almach | γ And | 02 04 | +42 20 | 2.13 | ‒0.1 | +1.20 | K2 III |
| Hamal | α Ari | 02 07 | +23 28 | 2.00 | +0.2 | +1.15 | K2 III |
| Mira | ο Cet | 02 19 | ‒02 59 | 2.0 | ‒1.0 | +1.42 | M6 e |
| Polaris | α UMi | 02 32 | +89 16 | 2.02 | ‒4.6 | + 0.6 | F8 Ib |
| Algol | β Per | 03 08 | +40 57 | 2.2 | ‒0.3 | ‒0.1 | B8 V |
| Mirfak | α Per | 03 24 | +49 51 | 1.80 | ‒4.3 | +0.48 | F5 Ib |
| Aldebaran | α Tau | 04 36 | +16 30 | 0.85 | ‒0.3 | +1.54 | K5 III |
| Rigel | β Ori | 05 15 | ‒08 12 | 0.11 | ‒7.0 | ‒0.03 | B8 Ια |
| Capella | α Aur | 05 17 | +46 00 | 0.08 | +0.3 | +0.80 | G8 III |
| Bellalrix | γ Ori | 05 25 | +06 21 | 1.63 | ‒3.3 | ‒0.22 | B2 III |
| EINath | β Tau | 05 26 | +28 36 | 1.65 | ‒1.6 | ‒0.13 | B7 III |
| Mintaka | δ Ori | 05 32 | ‒00 18 | 2.19 | ‒6.1 | ‒0.21 | O9.5II |
| Alnilam | ε Ori | 05 36 | ‒01 12 | 1.70 | ‒6.2 | ‒0.19 | B0 Ια |
| Alnitak | ζ Ori | 05 41 | ‒01 57 | 1.79 | ‒5.9 | ‒0.21 | O9.5 Ib |
| Saiph | κ Ori | 05 48 | ‒09 40 | 2.05 | ‒6.8 | ‒0.18 | B0.5 Ια |
| Betelgeuse | α Ori | 05 55 | +07 24 | 0.50 | ‒5.6 | +1.86 | M2 Ιab |
| Menkalinan | β Aur | 06 00 | +44 57 | 1.90 | +0.6 | +0.03 | A2 IV |
| Mirzam | β CMa | 06 23 | ‒17 57 | 1.98 | ‒4.5 | ‒0.24 | Bl II |
| Canopus | α Car | 06 24 | ‒52 42 | ‒0.73 | ‒4.7 | +0.16 | F0 Ib |
| Alhena | γ Gem | 06 38 | +16 24 | 1.93 | +0.0 | +0.00 | A0 IV |
| Sirius | α CMa | 06 45 | ‒16 43 | ‒1.45 | +1.4 | +0.00 | Al V |
| Adhara | ε CMa | 06 59 | ‒28 58 | 1.50 | ‒5.0 | ‒0.22 | B2 II |
| Wezen | δ CMa | 07 08 | ‒26 24 | 1.84 | ‒7.3 | +0.67 | F8 Ιa |
| Castor | α Gem | 07 35 | +31 53 | 1.58 | +0.8 | +0.04 | Al V |
| Procyon | α CMi | 07 39 | +05 14 | 0.35 | +2.7 | +0.41 | F5 IV |
| Pollux | β Gem | 07 45 | +28 01 | 1.15 | +1.0 | +1.00 | K0 III |
| Naos | ζ Pup | 08 04 | ‒40 00 | 2.25 | ‒7.0 | ‒0.27 | Ο5.8 |
| ― | γ Vel | 08 10 | ‒47 20 | 1.83 | ‒4.0 | ‒0.26 | WC 7 |
| Avior | ε Car | 08 23 | ‒59 30 | 1.87 | ‒2.1 | +1.30 | K0 II |
| ― | δ Vel | 08 45 | ‒54 43 | 1.95 | +0.1 | +0.0 | A0 V4 |
| Suhail | λ Vel | 09 08 | ‒43 26 | 2.26 | ‒4.5 | +1.69 | K5 Ib |
| Miaplacidus | β Car | 09 13 | ‒69 43 | 1.68 | ‒0.4 | +0.00 | A0 III |
The brightest stars visible from Greece (cont.)
| Star | Designation | α (2000), h m | δ (2000), ° ′ | m(V), mag | M(V), mag | B−V | Spectral Type |
|---|---|---|---|---|---|---|---|
| Scutulum | ι Car | 09 17 | ‒59 16 | 2.24 | ‒4.5 | +0.18 | F0 Ib |
| Alphard | α Hya | 09 28 | ‒08 40 | 1.99 | ‒0.4 | +1.43 | K3 III |
| Regulus | α Leo | 10 08 | +11 58 | 1.35 | ‒0.6 | ‒0.11 | B7 V |
| Algeiba | γ Leo | 10 20 | +19 51 | 2.1 | ‒0.5 | +1.12 | K0 III |
| Dubhe | α UMa | 11 03 | +61 45 | 1.79 | ‒0.7 | +1.06 | K0 III |
| Denebola | β Leo | 11 49 | +14 34 | 2.14 | +1.6 | +0.09 | A3 V |
| Acrux | α Cru | 12 27 | ‒63 06 | 0.9 | ‒3.5 | ‒0.26 | Bl IV |
| Gacrux | γ Cru | 12 31 | ‒57 07 | 1.64 | ‒2.5 | +1.60 | M3 III |
| Muhlifain | γ Cen | 12 42 | ‒48 58 | 2.16 | ‒0.5 | ‒0.02 | A0 III |
| Mimosa | β Cru | 12 48 | ‒59 41 | 1.26 | ‒4.7 | ‒0.24 | B0 III |
| Alioth | ε UMa | 12 54 | +55 57 | 1.78 | ‒0.2 | ‒0.02 | A0 p |
| Mizar | ζ UMa | 13 24 | +54 56 | 2.09 | +0.0 | +0.03 | A2 V |
| Spica | α Vir | 13 25 | ‒11 09 | 0.96 | ‒3.4 | ‒0.23 | Bl V |
| ― | ε Cen | 13 40 | ‒53 28 | 2.30 | ‒3.6 | ‒0.23 | Bl V |
| Alkaid | η UMa | 13 48 | +49 19 | 1.86 | ‒1.9 | ‒0.19 | B3 V |
| Hadar | β Cen | 14 04 | ‒60 22 | 0.60 | ‒5.0 | ‒0.23 | Bl II |
| Menkent | θ Cen | 14 07 | ‒36 22 | 2.06 | +1.0 | +1.02 | K0 III |
| Arcturus | α Boo | 14 16 | +19 11 | ‒0.06 | ‒0.2 | +1.23 | K2 IIIp |
| Rigil Kent | α Cen | 14 40 | ‒60 50 | ‒0.1 | +4.3 | +0.7 | G2 V |
| Kochab | β UMi | 14 50 | +74 09 | 2.07 | ‒0.5 | +1.46 | K4 III |
| Alphecca | α CrB | 15 35 | +26 43 | 2.23 | +0.5 | ‒0.02 | A0 V |
| Antares | α Sco | 16 29 | ‒26 26 | 1.0 | ‒4.7 | +1.81 | Ml Ib |
| Atria | α TrA | 16 49 | ‒69 02 | 1.93 | ‒0.3 | +1.43 | K4 III |
| ― | ε Sco | 16 5O | ‒34 18 | 2.29 | +0.7 | +1.15 | Κ2 ΙΙΙ |
| Shaula | λ Sco | 17 34 | ‒37 06 | 1.62 | ‒3.4 | ‒0.22 | Bl IV |
| Ras‒Alhague | α Oph | 17 35 | +12 34 | 2.07 | +0.8 | +0.15 | A5 III |
| ― | θ Sco | 17 37 | ‒43 00 | 1.87 | ‒4.5 | +0.40 | FO Ι |
| Eltanin | γ Dra | 17 57 | +51 29 | 2.22 | ‒0.6 | +1.52 | K5 III |
| Kaus Australis | ε Sgr | 18 24 | ‒34 23 | 1.83 | ‒1.5 | ‒0.02 | B9 IV |
| Vega | α Lyr | 18 37 | +38 47 | 0.04 | +0.5 | +0.00 | AO V |
| Nunki | σ Sgr | 18 55 | ‒26 18 | 2.08 | ‒2.5 | ‒0.20 | B2 V |
| Altair | α Aql | 19 51 | +08 52 | 0.77 | +2.3 | +0.22 | A7 IV |
| Sadir | γ Cyg | 20 22 | +40 15 | 2.23 | ‒4.7 | +0.67 | F8 Ib |
| Peacock | α Pav | 20 26 | ‒56 44 | 1.93 | ‒2.9 | ‒0.20 | B3 IV |
| Deneb | α Cyg | 20 41 | +45 17 | 1.25 | ‒7.3 | +0.09 | A2 Ia |
| Al Na' ir | α Gru | 22 08 | ‒46 58 | 1.74 | +0.2 | ‒0.14 | B5 V |
| ― | β Gru | 22 42 | ‒46 53 | 2.20 | –1.5 | + 1.6 | M3 II |
| Fomalhaut | α PsA | 22 58 | ‒29 37 | 1.16 | +1.9 | +0.09 | A3 V |
The brightest stars of the sky with m(V) ≤ 1.00
| Star | Designation | α (2000), h m | δ (2000), ° ′ | m(V), mag | M(V), mag | B−V | Spectral Type |
|---|---|---|---|---|---|---|---|
| Sirius | α CMa | 06 45 | ‒16 43 | ‒1.45 | +1.4 | +0.00 | Al V |
| Canopus | α Car | 06 24 | ‒52 42 | ‒0.73 | ‒4.7 | +0.16 | F0 Ib |
| Rigil Kent | α Cen | 14 40 | ‒60 50 | ‒0.10 | +4.3 | +0.7 | G2 V |
| Arcturus | α Boo | 14 16 | +19 11 | ‒0.06 | ‒0.2 | +1.23 | K2 IIIp |
| Vega | α Lyr | 18 37 | +38 47 | 0.04 | +0.5 | +0.00 | AO V |
| Capella | α Aur | 05 17 | +46 00 | 0.08 | +0.3 | +0.80 | G8 III |
| Rigel | β Ori | 05 15 | ‒08 12 | 0.11 | ‒7.0 | ‒0.03 | B8 Ια |
| Procyon | α CMi | 07 39 | +05 14 | 0.35 | +2.7 | +0.41 | F5 IV |
| Achernar | α Eri | 01 38 | ‒57 15 | 0.48 | ‒1.6 | ‒0.18 | B5 IV |
| Betelgeuse | α Ori | 05 55 | +07 24 | 0.50 | ‒5.6 | +1.86 | M2 Ιab |
| Hadar | β Cen | 14 04 | ‒60 22 | 0.60 | ‒5.0 | ‒0.23 | Bl II |
| Altair | α Aql | 19 51 | +08 52 | 0.77 | +2.3 | +0.22 | A7 IV |
| Aldebaran | α Tau | 04 36 | +16 30 | 0.85 | ‒0.3 | +1.54 | K5 III |
| Acrux | α Cru | 12 27 | ‒63 06 | 0.90 | ‒3.5 | ‒0.26 | Bl IV |
| Spica | α Vir | 13 25 | ‒11 09 | 0.96 | ‒3.4 | ‒0.23 | Bl V |
| Antares | α Sco | 16 29 | ‒26 26 | 1.00 | ‒4.7 | + 1.81 | Ml Ib |
Условие
A star has an effective temperature K, absolute magnitude and apparent magnitude . Find
a the star’s distance, ,
b its luminosity, , and
c its radius, . (Ignore extinction).
Решение
(a) Its distance is calculated from equation: ,
or and pc. (3 Points)
(b) Its Luminosity is calculated from equation:
or
or and erg sec⁻¹. (4 Points)
(c) Its radius can be easily calculated from equation: , from which
from which we get: cm. (3 Points)
Теми и трудност
Трудност: неоценена.
Звезди · Свойства на звездите
Предпоставки: Разширена олимпиадна подготовка
Оригинал в Архива: ShortQuestions.pdf · допълнителни данни: IOAA7-Constants.doc · допълнителни данни: IOAA7-BrightStars-list.docx