Mira vs Polaris
| Thuộc Tính | Mira | Polaris |
|---|---|---|
| Ký Hiệu | 68Omi Cet | 1Alp UMi |
| Chòm Sao | N/A | N/A |
| Phân Loại Quang Phổ | Class M — M-type (Red) | Class F — F-type (Yellow-White) |
| Cấp Sao Biểu Kiến | +6.47 | +1.97 |
| Cấp Sao Tuyệt Đối | 1,66 | -3,64 |
| Khoảng Cách | 299 ly | 433 ly |
| Khối Lượng | N/A | N/A |
| Bán Kính | N/A | N/A |
| Nhiệt Độ | N/A | N/A |
| Độ Sáng | N/A | N/A |
Sự Khác Biệt Chính
- ◆ Both are famous variable stars in the northern sky, though entirely different types.
- ◆ Polaris is a Cepheid variable that pulsates predictably and was used to calibrate the Cepheid distance ladder.
- ◆ Mira is a long-period Mira-type variable that can range from naked-eye visibility to complete invisibility.
- ◆ Polaris is celebrated as the North Star for its positional stability near the pole; Mira is celebrated as the first recognized variable star (1596).
- ◆ Polaris's pulsation amplitude has been shrinking over the past century; Mira continues its large-amplitude cycle.