Highlights of the Messier catalog, seen on Slooh robotic telescope

3. Labeled All-sky View

4. Crab Nebula (M1) – T1 hm Supernova remnant in constellation Taurus Distance: 6500 LY Size of nebula: about 15 LY Size of pulsar (neutron star) at center: about 10-15 km Supernova witnessed by Chinese and possibly by native Americans Nebula discovered in 1731 by John Bevis of London, then independently by Charles Messier in 1758

5. Crab Nebula (M1) – T1 wf Supernova remnant in constellation Taurus Distance: 6500 LY Size of nebula: about 15 LY Size of pulsar (neutron star) at center: about 10-15 km Nebula discovered in 1731 by John Bevis of London, then independently by Charles Messier in 1758 Nebula in center of this wide-field view; bright star Zeta Tauri is below/left of nebula

6. Rich Globular Cluster (M3) – T2 hm Globular cluster in constellation Canes venatici Distance: 30,000 LY Size: 160 LY Age: 12-14 billion years Discovered by Charles Messier in 1764

7. Rich Globular Cluster (M3) – T1 hm Globular cluster in constellation Canes venatici Distance: 30,000 LY Size: 160 LY Age: 12-14 billion years Mass: about 800,000 solar masses One of the largest globular clusters known

8. Velvet Cluster (M46 ) – T1 hm Open cluster in constellation Puppis Distance: 5000 LY Size: 40 LY Age: 300 million years Discovered by Charles Messier in 1771 High-mag view shows center of cluster Planetary nebula NGC 2438 is not part of cluster; it is apparently a foreground object, estimated distance 3000 LY

9. Velvet Cluster (M46 ) – T1 wf Open cluster in constellation Puppis Distance: 5000 LY Size: 40 LY Age: 300 million years Discovered by Charles Messier in 1771 Wide-field view shows M46 at center, M47 at right, NGC 2423 above M47 Distance of M47: 2000 LY Size of M47: 18 LY

10. Whirlpool Galaxy (M51 ) – T2 hm Spiral galaxy in constellation Canes venatici Distance: 30 million LY Size: 100,000 LY Discovered by Charles Messier in 1773 Companion galaxy NGC 5195 (seen at top) discovered by Pierre Mechain in 1781 Messier described M51 as “a very faint nebula, without stars”; following Mechain’s discovery, Messier revised his description as a “double nebula” Bright spots (not seen by Messier) in spiral arms are star-forming regions

11. Whirlpool Galaxy (M51 ) – T2 wf Spiral galaxy in constellation Canes venatici Distance: 30 million LY Size: 100,000 LY Discovered by Charles Messier in 1773 Companion galaxy NGC 5195 discovered by Pierre Mechain in 1781 Spiral structure first detected by Lord Rosse in 1845, using a 72-inch aperture telescope, the “Leviathan”

12. Spiral Galaxy M65 – T1 hm Spiral galaxy in constellation Leo Distance: 35 million LY Size: 90,000 LY Discovered by Charles Messier in 1780 Member of the “Leo Trio”, a group of three interacting galaxies

13. “ The Leo Trio” – T2 wf Group of spiral galaxies in constellation Leo Distance: 35 million LY In this wide-field view, M65 is seen at center, M66 at left, NGC 3628 at top Size of galaxies: M65: 90,000 LY M66: 90,000 LY NGC 3628: 130,000 LY M65 and M66 discovered by Charles Messier in 1780 NGC 3628 discovered by William Herschel in 1784

14. Owl Nebula (M97) – T1 hm Planetary nebula in constellation Ursa major Distance: 2000 LY Complex structure: 3 elliptical shells of gas around central white dwarf star, which ionizes and illuminates them Discovered by Pierre Mechain in 1781

15. Owl Nebula (M97) – T2 wf Planetary nebula in constellation Ursa major Distance: 2000 LY In this wide-field view, nebula M97 is seen at bottom left, and spiral galaxy M108 at top right Both were discovered by Pierre Mechain in 1781, but Messier did not include the galaxy in the final edition of his catalog Based on Messier’s notes, M108 was added to catalog in 1953 Distance of M108: 40 million LY Size of M108: 100,000 LY

16. Sky Safari – A Slooh Production by Kochava Yerushalmit