Glossary term: 星等
Description: 在天文学中，星等是衡量一个天体亮度的单位。天文学中使用的星等系统起源于古代，是对恒星从最亮到最暗的排序。这也是为什么星等值越小（或越负）意味着天体越亮，而数字越大意味着天体越暗。因此，-1 等的恒星比 0 等的恒星更亮，而 0 等的恒星又比 1 等的恒星更亮。
星等采用对数刻度，5 等的差异相当于我们能接收到的能量相差 100 倍，即10 等的恒星比 5 等的恒星暗 100 倍。
星等有不同的类型，视星等表征天体的视亮度，它取决于天体的光度（天体发出光的强度）以及天体与地球的距离。
相比之下，绝对星等是指如果将天体放置在距离地球为 10 秒差距（32.6 光年）处，我们测量的视星等。(对于小行星等反射辐射的天体，则有不同的定义）。
实际上，星等是针对通过特定滤光片观测到的天体的亮度而规定的，与天体在特定波长范围内的亮度相对应。有许多 "测光系统 "用于指定滤光片和相应的星等。 相比之下，热星等是对天体亮度的直接测量：单位时间内发射的总电磁能量。而目视星等与人眼感知到的亮度相对应。
Related Terms:
See this term in other languages
Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher The translation of this term and its definition is still awaiting approval
The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".
If you notice a factual or translation error in this glossary term or definition then please get in touch.
Related Activities
How Light Pollution Affects the Stars: Magnitude Readers
astroEDU educational activity (links to astroEDU website) Description: Build a Magnitude Reader to explore the magnitude of stars.
License: CC-BY-4.0 Creative Commons 署名 4.0 国际 (CC BY 4.0) icons
Tags:
Hands-on
, Dark skies
, ecology
Age Ranges:
10-12
, 12-14
, 14-16
, 16-19
Education Level:
Middle School
Areas of Learning:
Modelling
, Observation based
Costs:
Medium Cost
Duration:
1 hour
Group Size:
Group
Skills:
Asking questions
, Planning and carrying out investigations
Let's play with powers of 10
astroEDU educational activity (links to astroEDU website) Description: A game of cards to understand powers of 10 and the very diverse scales in Nature
License: CC-BY-4.0 Creative Commons 署名 4.0 国际 (CC BY 4.0) icons
Tags:
Scales
, Game
, Distances
, size
, Power
, length
Age Ranges:
12-14
, 14-16
, 16-19
, 19+
Education Level:
Informal
, Secondary
, University
Areas of Learning:
Guided-discovery learning
, Social Research
Costs:
Low Cost
Duration:
2 hours
Group Size:
Group
Skills:
Analysing and interpreting data
, Asking questions
