Astronomical Info / 天文資訊 > Special Astronomical Events / 特別天文事件 > Partial Lunar Eclipse of April 26th, 2013 | 2013 年 4 月 26 日之月偏食 [Refresh 更新]

Quick info 快速資訊: Eclipse time at Hong Kong 香港可見月食時間 : 2013/04/26 02:04 - 05:59 HKT

Quick links 快速連結:
- Information about the eclipse 是次月食資料
- Local (HK) circumstances 本地 (香港) 情況 - Future lunar eclipses 未來月食
- Lunar eclipse basic knowledge 月食基礎知識 - More eclipse info 更多日月食資訊

Information about the eclipse 是次月食資料

A very brief partial lunar eclipse will occur on April 26 (April 25 in UTC), and is generally visible in Europe, Africa, Oceania and most of Asia. It will not be visible in most of the Americas; eastern parts of South America will experience only the penumbral phase that takes place after the brief partial eclipse.

本年 4 月 26 日 (協調世界時 4 月 25 日) 將出現一次非常短暫的月偏食。月食整個過程於歐洲、非洲、大洋洲及亞洲大部分地區可見,但美洲絕大部分地區將不能見到是次月食;南美東部只能見到於偏食之後出現的半影月食。

Map courtesy of NASA 月食圖由美國太空總署提供

The following shows some general details about the eclipse:

下表列出是次月食的一般性資料 :

Eclipse series and characteristics
Saros series number 沙羅序列號碼 112 (occurring at ascending node 升交點月食)
Member in the series 序列中次數 65 out of 72 | 72 次中的第 65 次
Gamma 伽馬數 -1.0121 earth radii 地球半徑
Time in UTC/HKT
時間 (世界協調時 / 香港時間)
P1 - Moon enters Earth's penumbra (penumbral eclipse starts)
P1 - 月球進入地球的半影 (半影月食開始)
04/25 18:03:41 UTC; 04/26 02:03:41 HKT
U1 - Moon enters Earth's umbra (partial eclipse starts)
U1 - 月球進入地球的本影 (初虧,月偏食開始)
04/25 19:54:04 UTC; 04/26 03:54:04 HKT

Greatest eclipse

04/25 20:07:29 UTC; 04/26 04:07:29 HKT

U4 - Moon fully leaves Earth's umbra (partial eclipse ends)
U4 - 整個月球離開地球的本影 (復圓,月偏食結束)

04/25 20:21:04 UTC; 04/26 04:21:04 HKT
P4 - Moon fully leaves Earth's penumbra (penumbral eclipse ends)
P4 - 整個月球離開地球的半影 (半影月食結束)
04/25 22:11:23 UTC; 04/26 06:11:23 HKT
Information at greatest eclipse
食甚 (食分最大) 時資料
Time 時間 04/25 20:07:29 UTC; 04/26 04:07:29 HKT
Penumbral Magnitude (P) and Umbral Magnitude (U) 半影食分 (P) 和本影食分 (U) P: 0.9866; U: 0.0148

All places that can observe this eclipse (no matter what the Moon's position is) will experience the aforementioned events in the times indicated above.


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Local (HK) circumstances 本地 (香港) 情況

Observers in Hong Kong will experience most parts of the eclipse after 2 am, ending with moonrise at 5:59 am. However the partial stage is very brief, lasting only 27 minutes with only 1.5% of the lunar diameter entering the Earth's umbral shadow. This also means that it will be hard to observe noticeable difference during the eclipse with naked eyes.

The eclipse is best viewed at locations not obscured to the southwest / west-southwest.

於香港的觀測者可於凌晨 2 時過後看到月食的大部分過程,至上午 5 時 59 分月落為止。可是,是次月食之偏食階段非常短暫,維時只有 27 分鐘,月球更只得約百分之 1.5 的直徑會進入地球的本影區。在此情況下只靠肉眼難以察覺月球於月食時之變化。


The details are summarized in the following table:

詳細資料整理如下 :

Event for Hong Kong
Time in HKT
Lunar Altitude and Azimuth
Moon enters Earth's penumbra (penumbral eclipse starts)
月球進入地球的半影 (半影月食開始)
04/26 02:04 Altitude 高度 : 44°
Azimuth 方位角 : 219° (SW 西南)
Moon enters Earth's umbra (partial eclipse starts)
月球進入地球的本影 (初虧,月偏食開始)
04/26 03:54 Altitude 高度 : 25°
Azimuth 方位角 : 240° (WSW 西南偏西)

Greatest eclipse

04/26 04:07 Altitude 高度 : 22°
Azimuth 方位角 : 242° (WSW 西南偏西)
Moon fully leaves Earth's umbra (partial eclipse ends)
整個月球離開地球的本影 (復圓,月偏食結束)
04/26 04:21 Altitude 高度 : 20°
Azimuth 方位角 : 244° (WSW 西南偏西)
Moonset (penumbral eclipse in progress)
月落 (半影月食進行中)
04/26 05:59 Altitude 高度 : -1°
Azimuth 方位角 : 254° (WSW 西南偏西)
Information at greatest magnitude for Hong Kong
Type 類型 Partial 月偏食
Time 時間 04:07 HKT
Direction of shadow relative to the Moon 地球影子方向 (相對於月球)

(Umbral magnitude too small to be meaningful 由於本影食分太小,此欄沒有重要意義)

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Future lunar eclipses 未來月食

Lunar eclipses in the next five years (click on the date to see the visible areas for that eclipse):

未來五年的月食資料 (請按下日期以觀看月食可見範圍) :

Date (UTC)
日期 (世界協調時)
Eclipse type
Eclipse type at HK
Time of greatest eclipse
2013/05/25 Penumbral 半影月食 P: 0.0402; U: -0.9279 --- ---
2013/10/18 Penumbral 半影月食 P: 0.7908; U: -0.2666 Penumbral 半影月食 10/19 06:22 (moonset 月落)
2014/04/15 Total 月全食 P: 2.3182; U: 1.2907 --- ---
2014/10/08 Total 月全食 P: 2.1456; U: 1.1659 Total 月全食 18:55
2015/04/04 Total 月全食 P: 2.0792; U: 1.0008 Total 月全食 20:00
2015/09/28 Total 月全食 P: 2.2296; U: 1.2764 --- ---
2016/03/23 Penumbral 半影月食 P: 0.7747; U: -0.3118 Penumbral 半影月食 19:47
2016/09/16 Penumbral 半影月食 P: 0.9080; U: -0.0635 Penumbral 半影月食 09/17 02:54
2017/02/11 Penumbral 半影月食 P: 0.9884; U: -0.0354 Penumbral 半影月食 06:54 (moonset 月落)
2017/08/07 Partial 月偏食 P: 1.2886; U: 0.2464 Partial 月偏食 08/08 02:20
2018/01/31 Total 月全食 P: 2.2941; U: 1.3155 Total 月全食 21:30

* P represents penumbral magnitude while U represents umbral magnitude.
* P 和 U 分別代表半影食分和本影食分。

A penumbral eclipse will be visible in Hong Kong in October this year, while the next tetrad will occur in 2014 and 2015 with two visible in Hong Kong.

本港將於 10 月出現一次半影月食,而下一組連續四次全食將於 2014 / 2015 年出現,其中兩次於香港可見。

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Lunar eclipse basic knowledge 月食基礎知識

The following information is quoted from Wikipedia. 以下資料摘自維基百科

A lunar eclipse occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital nodes.


The shadow of the Earth can be divided into two distinctive parts: the umbra and penumbra. Within the umbra, there is no direct solar radiation. However, as a result of the Sun's large angular size, solar illumination is only partially blocked in the outer portion of the Earth's shadow, which is given the name penumbra.

A penumbral eclipse occurs when the Moon passes through the Earth's penumbra. The penumbra does not cause any noticeable darkening of the Moon's surface, though some may argue it turns a little yellow. A special type of penumbral eclipse is a total penumbral eclipse, during which the Moon lies exclusively within the Earth's penumbra. Total penumbral eclipses are rare, and when these occur, that portion of the Moon which is closest to the umbra can appear somewhat darker than the rest of the Moon.

A partial lunar eclipse occurs when only a portion of the Moon enters the umbra. When the Moon travels completely into the Earth's umbra, one observes a total lunar eclipse. The Moon's speed through the shadow is about one kilometer per second (2,300 mph), and totality may last up to nearly 107 minutes. Nevertheless, the total time between the Moon's first and last contact with the shadow is much longer, and could last up to 3.8 hours. The relative distance of the Moon from the Earth at the time of an eclipse can affect the eclipse's duration. In particular, when the Moon is near its apogee, the farthest point from the Earth in its orbit, its orbital speed is the slowest. The diameter of the umbra does not decrease much with distance. Thus, a totally-eclipsed Moon occurring near apogee will lengthen the duration of totality.

The Moon does not completely disappear as it passes through the umbra because of the refraction of sunlight by the Earth's atmosphere into the shadow cone; if the Earth had no atmosphere, the Moon would be completely dark during an eclipse. The red colouring arises because sunlight reaching the Moon must pass through a long and dense layer of the Earth's atmosphere, where it is scattered. Shorter wavelengths are more likely to be scattered by the small particles, and so by the time the light has passed through the atmosphere, the longer wavelengths dominate. This resulting light we perceive as red. This is the same effect that causes sunsets and sunrises to turn the sky a reddish colour; an alternative way of considering the problem is to realise that, as viewed from the Moon, the Sun would appear to be setting (or rising) behind the Earth.

The amount of refracted light depends on the amount of dust or clouds in the atmosphere; this also controls how much light is scattered. In general, the dustier the atmosphere, the more that other wavelengths of light will be removed (compared to red light), leaving the resulting light a deeper red colour. This causes the resulting coppery-red hue of the Moon to vary from one eclipse to the next. Volcanoes are notable for expelling large quantities of dust into the atmosphere, and a large eruption shortly before an eclipse can have a large effect on the resulting colour.




  1. 半影食始:月球剛剛和半影區接觸,這時月球表面光度略為減少,但肉眼較難覺察。
  2. 初虧:月球由東緣慢慢進入地影,月球與地球本影第一次外切。
  3. 食既:月球進入地球本影,並與本影第一次內切。
  4. 食甚:月圓面中心與地球本影中心最接近的瞬間,此時前後月球表面呈紅銅色或暗紅色。(原因:大陽光經過地球大氣層時發生折射,使光線向內側偏折,但每種光的偏折程度不一樣(色散),紅光偏折程度最大,最接近地球陰影,映在月球上;此外,由於大氣層的灰塵及雲的含量與位置不同,光線偏折程度會有不同,因此月全食時的月球是暗紅、紅銅、或橙色的。同樣的道理,由於大氣層的折射,朝陽與夕陽不是白色的,而根據高度因為大氣折射程度不同,呈現橙色或紅色。)
  5. 生光:月球在地球本影內移動,並與地球本影第二次內切。
  6. 復圓:月球逐漸離開地球本影,與地球本影第二次外切。
  7. 半影食終:月球離開半影,整個月食過程正式完結。


Please read the Wikipedia article for more. 欲得到更多資料,請瀏覽相關條目

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More eclipse info 更多日月食資訊

For more information on eclipses, visit our "Eclipse Q&A" section (total 3 pages) and "Eclipse Dates and Numbers - Lunar Eclipse".

如欲得知更多有關日月食的資訊,請到本網的 "日月食問與答" 一節 (共三頁) 和 "月食日期和數字"。

Eclipse times and information are based on Eclipse Predictions by Fred Espenak, NASA's GSFC. NASA's lunar eclipse page: here.

Last Accessed 最近訪問日期: Sun Oct 01 2023 12:55:26 HKT
Last Modified 最近修訂日期: Mon Jul 24 2023