Caption: 這張圖片展示了兩顆相互作用的漩渦星系，它們距離地球大約1.5億光年。兩顆漩渦星系在引力的牽引下“共舞”，使得它們的旋臂出現了明顯的扭曲。這幅圖像中所展現的“擁抱”，最終將以兩個星系合併為一個星系而結束，極有可能形成一個橢圓星系。
Credit: 歐空局 credit link

Caption: The zodiac constellation Leo and its surrounding constellations. Starting from the top of the diagram and going clockwise, these are Leo Minor, Cancer, Sextans, Hydra, Crater, Virgo and Ursa Major. The brightest star in Leo, Regulus, lies almost exactly on the ecliptic (shown here as a blue line): the path the Sun appears to take across the sky over the course of a year. The Sun spends the period from mid August to mid September in Leo. The other planets in the Solar System can often be found in Leo. Leo spans the celestial equator and is thus part of it is visible at some time in the year from all of planet Earth with some of the constellation obscured for the most arctic and antarctic regions of the world. Leo is most visible in the evenings in the northern hemisphere spring and southern hemisphere autumn. Several objects can be seen in Leo, including M65 and M66 – two galaxies in the Leo Triplet, a trio of galaxies including NGC 3628, not listed here. In addition, M96, a spiral galaxy, can be seen as a fuzzy object using a small telescope, and Messier 105, an elliptical galaxy. Each of these objects are labelled on the map as red ellipses. The y-axis of this diagram is in degrees of declination with north as up and the x-axis is in hours of right ascension with east to the left. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labelled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. Neither the constellation boundaries, nor the line marking the ecliptic, nor the lines joining the stars appear on the sky.
Credit: Adapted by the IAU Office of Astronomy for Education from the original by IAU/Sky & Telescope

Caption: The zodiac constellation Virgo and its surrounding constellations. Starting from the top of the diagram and going clockwise, these are Coma Berenices, Leo, Crater, Corvus, Libra, and Bootes. The brightest star in Virgo, Spica, lies just below the ecliptic (shown here as a blue line) in the middle of the map. One way of locating this star in the night sky is to follow the handle of the Big Dipper to the star Arcturus in Bootes and go along a line straight down to Spica (“arc to Arcturus and spike to Spica”). This star lies just below the ecliptic. The ecliptic is the path the Sun appears to take across the sky over the course of a year. The Sun is in Virgo from mid September to late October. The other planets of the Solar System can often be found in Virgo. Virgo spans the celestial equator and is thus part of it is visible at some time in the year from all of planet Earth with some of the constellation obscured for the most arctic and antarctic regions of the world. Virgo is most visible in the evenings in the northern hemisphere spring and southern hemisphere autumn. The constellation Virgo appears as a person lying with their back roughly against the ecliptic, arms outstretched, and feet pointed east. Several deep-sky objects are visible in Virgo, including NGC4697, M49, M87, M86, M84, and M60, all of which are labelled as red ellipses on the map. These are all spiral and elliptical galaxies located several millions of lightyears from Earth. Most notably, M87 is host to the supermassive black hole (Pōwehi) that was imaged by the Event Horizon Telescope in 2019. All of these galaxies are members of the Virgo Cluster, the nearest cluster of galaxies to the Milky Way. The y-axis of this diagram is in degrees of declination with north as up and the x-axis is in hours of right ascension with east to the left. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labelled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. Neither the constellation boundaries, nor the line marking the ecliptic, nor the lines joining the stars appear on the sky.
Credit: Adapted by the IAU Office of Astronomy for Education from the original by IAU/Sky & Telescope

Caption: 大熊座及其明亮恆星與周邊星座示意圖。從頂部開始沿順時針方向，大熊座周邊的星座依次為：天龍座、鹿豹座、天貓座、小獅座、獅子座、後發座、獵犬座和牧夫座。大熊座中有著名為“北斗七星”的醒目星群，這也是大熊座最著名的標誌。這個醒目的北天星群在全球不同文化中擁有豐富多樣的名稱。儘管大多數星座和星群中的恆星是互不關聯的，它們在天球上投影出的圖案其實僅是出於巧合，但北斗七星中的五顆恆星同屬“大熊座移動星群”——這些恆星在宇宙中同步運動，很可能在3億年前形成於同一區域。圖中北斗右側末端的兩顆星構成“指極星”，可由它們的連線找到位於小熊座的北極星。 作為北天星座，大熊座在北半球和赤道地區都是可見的。除南極地區外，南半球的部分區域也可觀測到大熊座的局部，但南半球溫帶地區並不都能看到完整的北斗七星。而在北極和北半球大多數溫帶地區，北斗七星以及大熊座的其他主要部分則處於恆顯圈內。大熊座的最佳觀測期為北半球春季與南半球秋季。 大熊座的北部有兩個易於觀測的星系，在圖中以紅色橢圓標注：旋渦星系M81和可能同為旋渦星系的M82。由於M82的側方朝向地球，我們難以通過觀測確定其結構。行星狀星雲M97（貓頭鷹星雲）位於大熊座中央，在圖中以疊加了十字符號的綠色圓圈標注。 該圖的縱軸為赤緯，橫軸為赤經，方向為上北下南左東右西。圖中標注的恆星大小對應其視星等——衡量天體視亮度的標準，較大的圓點代表著較亮的恆星。圖中的希臘字母標注著星座中最亮的恆星。這些恆星按亮度排序，最亮的一般被標記為α星，第二亮的一般為β星，等等，不過這種字母排序並不總是和實際亮度排序完全一致。圖中虛線標注的是國際天文學聯合會劃定的星座邊界，綠色實線則是一種常見的星座形象連線。需要注意的是，在實際觀測時，這些邊界與連線都不會出現在天空中。
Credit: 國際天文學聯合會天文教育辦公室（IAU OAE）根據國際天文學聯合會和《天空與望遠鏡》的原文改編

Caption: The constellation Camelopardalis with its bright stars and surrounding constellations. Camelopardalis is surrounded by (going clockwise from the top): Cepheus, Cassiopea, Perseus, Auriga, Lynx, Ursa Major, Draco and Ursa Minor. Camelopardalis is a large constellation but contains relatively few bright stars. Camelopardalis is a northern constellation and as such the whole constellation is visible for the whole northern hemisphere at some point in the year. It is also visible from equatorial parts of the southern hemisphere with some parts visible to temperate southern regions. The whole constellation is circumpolar for all arctic and more northerly temperate regions of the northern hemisphere. Camelopardalis is best viewed in the evening in the late northern hemisphere winter and late southern hemisphere summer. The spiral galaxies NGC 2403 and IC 342 lie in Camelopardalis and are marked here with red ellipses. This diagram maps an area around the north celestial pole. Here lines of constant right ascension converge. The right ascension values of these lines are marked on the x-axis above and below the diagram. Some of the lines of constant declination are marked on the y-axis. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labeled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. Neither the constellation boundaries, nor the lines joining the stars appear on the sky.
Credit: Adapted by the IAU Office of Astronomy for Education from the original by the IAU and Sky & Telescope

Caption: The constellation Cepheus along with its bright stars and surrounding constellations. Cepheus is surrounded by (going clockwise from the top): Camelopardalis, Ursa Minor, Draco, Cygnus, Lacerta and Cassiopeia. Cepheus is a large constellation. Its most notable star is Delta Cephei, the prototype for the class of variable stars known as Cepheid variables. These are variable stars which can be used to estimate distances both within our galaxy and to nearby galaxies. Cepheus lies close to the north celestial pole. As such it is circumpolar for arctic and temperate regions of the northern hemisphere. The whole of the constellation is also visible at some point in the year in equatorial regions of the northern hemisphere with parts of it visible in equatorial regions of the southern hemisphere. It is best viewed in the evening in the northern hemisphere late autumn and southern hemisphere late spring. The open cluster NGC 188 lies in Cepheus and is marked here with a yellow circle. The nebula NGC 7023 also lies in the constellation and is marked with a green square. The red ellipse in the lower right marks the position of the spiral galaxy NGC 6946. This diagram maps an area around the north celestial pole. Here lines of constant right ascension converge. The right ascension values of these lines are marked on the x-axis above and below the diagram. Some of the lines of constant declination are marked on the y-axis. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. Delta Cephei is marked with a circle around a dot as it is a variable star. Mu Cephei is also a variable star marked here as an open circle. These are ranked by brightness with the brightest star being labeled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. Neither the constellation boundaries, nor the lines joining the stars appear on the sky.
Credit: Adapted by the IAU Office of Astronomy for Education from the original by the IAU and Sky & Telescope