IOAA 2013, Теория, кратки задачи — Задача 8
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 binary system of stars consists of star (a) and star (b) with brightness ratio 2. The binary system is difficult to resolve and is observed from the Earth as one star of 5th magnitude. Find the apparent magnitude of each of the two stars ().
Решение
The apparent magnitude of star (a) is , of star (b) is and that of the system as a whole is . The corresponding apparent brightnesses are , and . For star (a):
and because , we get or
and finally mag. (5 point)
Similarly for star (b):
and because , we get or
and finally mag. (5 Point)
Теми и трудност
Трудност: неоценена.
Звезди · Двойни звезди
Предпоставки: Разширена олимпиадна подготовка
Оригинал в Архива: ShortQuestions.pdf · допълнителни данни: IOAA7-Constants.doc · допълнителни данни: IOAA7-BrightStars-list.docx