Никола 2019, 28 септември — Задача 4. 7. Radial velocity.
28 септември 2019г.
Внимание: Бележка към темата
Фиг. 3 (крива на лъчевата скорост на δ Cephei), спомената в задача „Цефеида“, липсва в източника.
Условие
A cepheid has its mean apparent magnitude of . Spectroscopic observations for this cepheid were carried out during 16 successive nights. The list of observations is given in the table, where the radial velocity is given in heliocentric system. Make such a plot based on the data listed in this table which enables you to derive several important characteristics of this cepheid and to answer the question: Could this cepheid be seen by the first people on the Earth (about 2 million years ago)? (The answer should be written in English: Yes or No.) What was the apparent magnitude of this star at that time?
Supplementary information: Use the relation showed in the plot below (this relation is valid for cepheids – pulsating stars).
Recommendations: Interstellar absorption and possible changes of the cepheid mean luminosity during the last 2 million years can be ignored.
| Moment of observations (in part of days) | Observed radial velocity, km/s |
|---|---|
| 0.9 | 75 |
| 1.8 | 74 |
| 2.9 | 51 |
| 3.9 | 45 |
| 4.9 | 67 |
| 5.8 | 75 |
| 6.8 | 63 |
| 7.8 | 46 |
| 8.8 | 47 |
| 8.9 | 50 |
| 9.8 | 70 |
| 10.8 | 70 |
| 11.9 | 53 |
| 12.8 | 42 |
| 13.8 | 42 |
| 14.8 | 58 |
| 15.9 | 75 |
Решение
Внимание: Непълно решение
В архива липсва файл с решения
Оригинал в Архива: 28092019.pdf