觀星入門
Introduction to Stargazing

 

你有試過在香港的郊野公園觀星嗎?雖然大家住在世界上最繁忙的城市之一,但隱藏在夜空中的宇宙奧秘一直在等著大家去發掘。我們希望可向有興趣展開美妙觀星之旅的人士提供一些貼士。在今期,我們會介紹一些觀星的重要工具。

Have you ever watched the stars in the countryside of Hong Kong? Although we are living in one of the busiest cities in the world, the universe is hiding mysteriously beyond the night sky and is waiting for us to explore. We would like to offer some basic tips for people who are interested in embarking on a wonderful journey through the starry sky. In this issue, we will introduce some important tools for stargazing.

1. 星圖 Star chart       

星圖包含了在特定時間和地點可見的星座名稱、位置、形狀等資料。而旋轉星圖則可模擬星空的運動,顯示在特定地點不同時間可看的星空。星圖可在香港太空館網頁下載。

A star chart contains information including the name, position and pattern of all constellations that are visible at a specific time and location. A rotating star chart can simulate the motion of the sky and show the night sky at any time in a specific location. Star chart can be downloaded from the website of the Hong Kong Space Museum.

Star chart produced by the Hong Kong Space Museum

香港太空館製作的星圖
Star chart produced by the Hong Kong Space Museum.

下載 Download

star chart

小巧好用的旋轉星圖
A compact and handy rotating star chart.

 

2. 紅光電筒 Red Light Torch

在黑暗的環境,基於安全理由,是應該要準備電筒的。但在觀星時,我們應盡量保持環境黑暗。我們的瞳孔在黑暗環境下會放大,能更清晰地看附近的景物及觀星。任何閃燈,即使時間很短,皆會影響眼睛的適應性,甚至會為眼睛帶來嚴重損害。由於眼晴對紅光的敏感度較低,當有必要於觀星時照明,例如閱讀星圖時,請使用紅光電筒。

In a dark environment, a torch should be prepared for safety purpose. During stargazing, however, we should keep the environment as dark as possible. Our pupils get wider in the dark so we can see the surroundings and watch the stars more clearly. Any flash light, no matter how short the duration, would affect the adaptability of our eyes and may cause serious damage to them. When lighting is required during stargazing, for example, in reading the star chart, please use red light torch as our eyes are less sensitive to red light.

red light head torch

使用紅光的掛頭燈十分方便

Using a red light head torch is very convenient.

 

 

Small tools that emit red light

能發出紅光的小工具也是觀星時的好幫手

Small tools that emit red light are helpful during stargazing.

 

 

3. 雙筒望遠鏡 Binoculars

即使沒有雙筒望遠鏡,我們的肉眼能在最佳條件下看到數以千計的星星。然而,雙筒望遠鏡可揭示星空中的細小特徵,並讓我們更清晰地欣賞月球及行星。當選擇雙筒望遠鏡時,我們基本上留意口徑、放大率及塗層。口徑較大的鏡片有利於看到更多星星,但對入門者而言,不同的雙筒望遠鏡口徑和放大率不會有太大不同。而塗層能減低被透鏡反射的光線量,觀星用的雙筒望遠鏡應讓較多的光線可穿過透鏡。檢測時,只需看看前鏡,好的觀星用雙筒望遠鏡塗層會令鏡片不會如鏡子般令你看到自己的樣子。

Our eyes can see thousands of stars under perfect conditions without using a pair of binoculars. However, binoculars can reveal extremely small features in the starry sky and allow us to observe the Moon and planets with great clarity. When choosing binoculars, we should pay attention to the aperture, magnification and coating on the lenses. Although large aperture binoculars allow more stars to be seen, the aperture and magnification of different binoculars do not vary too much for beginners. Coating helps to reduce the amount of light reflected by the lenses. For stargazing purposes, we would prefer more light to penetrate the lenses. During inspection, you may simply look at the front lenses of the binoculars. You should not see your own reflection on the ones with good lenses coating.

一支「12x50」的雙筒望遠鏡,代表雙筒望遠鏡的放大率為12倍,口徑為50毫米

A pair of “12x50” binoculars means it has a 12x magnification and a 50 mm aperture.

 

 

合適的塗層會令前鏡一般呈紫藍色

Suitable coating produces a purple-blue appearance on the front lenses.