Mekbudaについて
説明
Mekbuda, Zeta Geminorum, is a classical Cepheid variable — a yellow supergiant of spectral type G1 Ib that pulsates regularly between magnitudes 3.62 and 4.18 with a period of 10.15 days. It lies about 1,350 light-years away, and at maximum light it shines at roughly 3,000 solar luminosities. As a Cepheid, Mekbuda follows the period-luminosity relation that Henrietta Leavitt discovered in 1912 and that Edwin Hubble later used to measure galactic distances.
観測のコツ
Mekbuda is an ideal naked-eye Cepheid project: compare its brightness to Lambda Gem (3.58) and Nu Gem (4.15) every clear night and you can construct its own light curve in a few weeks. The variation is a full half magnitude — easily detected by eye. Mekbuda marks the western knee of Pollux, the southern Gemini twin. Best observed December through May.
歴史
The name comes from the Arabic "maqbūdah," meaning "the contracted" or "folded paw" — a pre-Islamic astronomical image of a lion's paw. The variability was discovered by Julius Schmidt in 1825. Mekbuda was one of the first Cepheid variables used to calibrate the period-luminosity relation: because it is close enough for accurate parallax measurement, it anchors the brightness scale that leads outward to other galaxies.
豆知識
Mekbuda's radius physically changes by about 10 percent during each 10-day cycle — the star actually swells and contracts as it pulsates. The Hubble Space Telescope's fine-guidance sensors directly measured its parallax in 2002, providing an independent check on the cosmic distance ladder. Mekbuda is one of only a handful of Cepheids bright enough for naked-eye monitoring; amateur observers have contributed meaningful data on tiny period changes over decades.
観測
1物理的性質
3変光の追いやすさ
| 機材 | ボートル3 | ボートル4 | ボートル5 |
|---|---|---|---|
| 肉眼 肉眼 | 困難+ | 困難+ | 困難 |
| 50mmファインダー 50mmファインダー | 普通 | 普通 | 普通 |
| 150mm望遠鏡 150mm望遠鏡 | 普通 | 普通 | 普通 |
ボートル3＝田舎 · 4＝郊外 · 5＝住宅地
5サーベイ画像
サーベイ画像を読み込み中…
6光度曲線
探究
9
サイズ比較
10
恒星を比較
11
スペクトル分類
13
恒星の進化
14
黒体放射スペクトル
15
恒星吸収スペクトル
スペクトル型に基づくシミュレーション吸収スペクトル。線にマウスを合わせると元素を識別できます。
16
恒星核融合
発見
17恒星メモ
18
光の旅タイムマシン
19
相対論的旅行
近くの天体
数度以内にある他の対象 — 望遠鏡を少し動かして探索を続けましょう。
可視性スコアは150 mmニュートン・ボートル4を前提としています。
