The document describes several astronomical objects in the constellation Andromeda, including: - The spiral galaxy NGC 891 which is 30 million light years away and 120,000 light years in diameter. - The elliptical galaxy NGC 404 which is 8 million light years away and was discovered by William Herschel in 1784. - The open star cluster NGC 752 which is around 1000 light years away and 1 billion years old. - The galaxy cluster Abell 262 which is 220 million light years away and contains several galaxies including NGC 703, 708, 705, and 704.

1. Sky Safari of the Constellation Andromeda

2. Labelled All-sky View

3. Caldwell 23 (NGC 891) – T1 hm Spiral Galaxy Distance 30 million LY Diameter 120,000 LY Discovered by Caroline Herschel in 1783 Dust lane is about 1500 LY across. The Milky Way Galaxy would look similar to this one if viewed edge-on from a similar distance.

4. Caldwell 23 (NGC 891) – T2 wf Spiral Galaxy Distance 30 million LY Diameter 120,000 LY Discovered by Caroline Herschel in 1783 In this wide field view, several faint galaxies are visible at bottom left, distance approximately 200 million LY.

5. Caldwell 23 (NGC 891) – T2 wf Spiral Galaxy Distance 30 million LY Diameter 120,000 LY Discovered by Caroline Herschel in 1783 Galaxies at bottom left (distance approximately 200 million LY) are labelled.

6. NGC 404 “Mirach’s Ghost” – T1 hm Elliptical Galaxy Distance 8 million LY Diameter 30,000 LY Discovered by William Herschel in 1784 Galaxy is the fuzzy object left of center Bright star at bottom left is Mirach (Beta Andromedae), type M0 red giant, distance 200 LY. (Faint reddish arc above Mirach is just glare from this very bright star.)

7. NGC 404 “Mirach’s Ghost” – T1 wf Elliptical Galaxy Distance 8 million LY Diameter 30,000 LY Discovered by William Herschel in 1784 In this wide-field view, Mirach is seen at the center, and NGC 404 is a faint fuzzy spot above/right of Mirach.

8. Golf Ball Cluster (NGC 752) – T1 wf Open Star Cluster Distance 1000 LY Diameter 15 LY Age 1 billion years Discovered by Giovanni Hodierna in 1654, later rediscovered by Caroline Herschel in 1783

9. Galaxy cluster Abell 262 – T1 hm Distance 220 million LY Diameter of cluster: 10 million LY (173 arc minutes) The group of galaxies at the center of this image includes (top to bottom) NGC 703, 708, 705, and 704. NGC 708, at the left of the group, is the brightest member. NGC 704 has a companion, NGC 704B. NGC 709 is slightly above/left of center NGC 714 is at the left edge of image NGC 700 is at bottom right.

10. Galaxy cluster Abell 262 (labelled) – T1 hm

11. Galaxy cluster Abell 262 (centered on NGC 700) – T1 hm Distance 220 million LY Diameter of cluster: 10 million LY (173 arc minutes) This view is a little west (right) of the labelled view. NGC 703, 708, 705, and 704 are seen at top left. NGC 700 is slightly left of center, with LEDA 6911 above center. LEDA 6928 is below NGC 700 LEDA 6886 is to the right of LEDA 6911 LEDA 6865 (UGC 1319) is towards the right of the picture

12. Galaxy cluster Abell 262 (centered on NGC 714) – T1 hm Distance 220 million LY Diameter of cluster: 10 million LY (173 arc minutes) This view is a little east (left) of the labelled view. NGC 714 is right of center. NGC 717 is left of center.

13. Galaxy cluster Abell 262 – T1 wf Distance 220 million LY Diameter of cluster: 10 million LY (173 arc minutes) The galaxies are very faint in this wide-field image, but the cluster covers an area of 3 degrees (the middle half of the image). Open cluster NGC 752 can be seen at top edge, left of center.

14. Open star cluster NGC 956 – T1 hm Distance unknown Diameter of cluster: 8 arc minutes (size in LY unknown) Discovered by John Herschel in 1831 The two bright stars at center are apparently foreground stars, a few hundred light years away.

15. Open star cluster NGC 956 – T1 wf Distance unknown Diameter of cluster: 8 arc minutes (size in LY unknown) Discovered by John Herschel in 1831 The cluster can be seen at the center of this wide-field image. At bottom left is open cluster M34, in Perseus.

16. Open star cluster NGC 7686 – T1 hm Distance 3000 LY Diameter 13 LY Discovered by William Herschel in 1787 Bright stars at center are foreground stars. Orange star at center is HD 221245, type K5 orange giant, mag 6.2, distance 850 LY Bright star at right is HD 221203, type K0 orange giant, mag 7.7, distance 1250 LY

17. Open star cluster NGC 7686 – T1 wf Distance 3000 LY Diameter 13 LY Discovered by William Herschel in 1787 Cluster faintly seen at center of this wide field image.

18. Blue Snowball (NGC 7662) – T2 hm Planetary nebula Distance 4000 LY Diameter 0.3 LY Age approximately 1000 years Discovered by William Herschel in 1784 This nebula exhibits a double ring structure: the inner ring is illuminated by a spherical shock wave, and the outer ring by ionization from the central star. The bright spots at the sides are FLIERs (Fast Low-Ionization Emission Regions).

19. Satellite Galaxy M110 – T1 hm Elliptical galaxy – companion to Andromeda Galaxy M31 Distance 2.5 million LY Diameter 10,000 LY Discovered by Caroline Herschel in 1783 (Was included by Messier in his drawing of M31 in 1773, but he did not record it in his list as a separate galaxy.)

20. Satellite Galaxy M32 – T2 hm Elliptical galaxy – companion to Andromeda Galaxy M31 Distance 2.5 million LY Diameter 6000 LY Discovered by Gillaume le Gentil in 1749, and included by Charles Messier in his catalog in 1773.

21. Andromeda galaxy M31 – T1 hm Spiral galaxy Distance 2.5 million LY Diameter 135,000 LY Known since antiquity, was recorded by Persian astronomer Al-Sufi in 964 Charles Messier added M31 and its companion M32 to his list in 1773 This high-mag view shows the core of the galaxy and details of the dust lane

22. Andromeda galaxy M31 – T2 wf Spiral galaxy Distance 2.5 million LY Diameter 135,000 LY Charles Messier added M31 and its companion M32 to his list in 1773 This wide-field image shows the spiral arms and dust lanes of M31. M32 is the fuzzy bright spot at bottom center. M110 is the faint fuzzy spot at top right.

23. Sky Safari – A Slooh Production by Kochava Yerushalmit