In the 19th century, amateur astronomers William and Margaret Huggins used the newly-discovered science of spectroscopy to analyze the composition of distant star clusters, nebulae, and galaxies.

1. Sky Safari: Andromeda by Kochava Yerushalmit

2. Sky Safari: Andromeda by Kochava Yerushalmit

3. Sky Safari: Andromeda by Kochava Yerushalmit
Labeled All-sky View

4. Sky Safari: Andromeda by Kochava Yerushalmit
Great Hercules Cluster (M13) – T1 hm
Globular cluster in
constellation Hercules
Distance: 25,000 LY
Size: about 120 LY
Age: about 12-14 billion
years
Contains about 600,000 solar
masses (probably around
100,000 very large stars)
Discovered by Edmond
Halley in 1714, and later
added to Messier’s list

5. Sky Safari: Andromeda by Kochava Yerushalmit
Sunflower Galaxy (M63) – T1 hm
Spiral galaxy in constellation
Canes Venatici
Distance: 30 million LY
Size: 100,000 LY
Contains about 140 billion
solar masses
Included by Lord Rosse in his
1850 list of 14 “nebulae” with
spiral structure
Discovered by Pierre
Mechain in 1779 - the first
object added by Mechain to
Messier’s list

6. Sky Safari: Andromeda by Kochava Yerushalmit
Cat’s Eye Nebula (NGC 6543) – T2 hm
Planetary nebula in
constellation Draco
Distance: 3000 LY
Central star is a Wolf-Rayet
star – a very hot star
(temperature around 100,000
K) in last stages of life,
ejecting mass at high speeds
(several thousand km/sec)
Complex structure includes
two expanding bubbles that
are perpendicular to each
other, surrounded by 9
spherical shells
Discovered by William
Herschel in 1786

7. Sky Safari: Andromeda by Kochava Yerushalmit
Mechain’s Galaxy (M106) – T2 hm
Barred spiral galaxy in
constellation Canes Venatici
Distance: 25 million LY
Size: 130,000 LY
“Active” galaxy with a central
black hole of 40 million solar
masses
Between the two visible arms
are two additional arms of hot
ionized gas, with no stars,
visible in x-rays
Discovered by Pierre
Mechain in 1781

8. Sky Safari: Andromeda by Kochava Yerushalmit
Spindle Galaxy (M102) – T2 hm
Lenticular galaxy in
constellation Draco
Distance: 50 million LY
Size: 90,000 LY
Lenticular galaxies have a
disk and central bulge like a
spiral, but no spiral arms; they
contain mostly old stars, with
little gas or dust
This galaxy was apparently
discovered by Pierre Mechain
in 1781; independently
discovered by William
Herschel in 1788

9. Sky Safari: Andromeda by Kochava Yerushalmit
Ghost of Jupiter (NGC 3242) – T2 hm
Planetary nebula in
constellation Hydra
Distance: around 2000 LY
Size: around 0.4 LY
Central star has a temperature
around 60,000 K and a mass
less than half of the sun
Discovered by William
Herschel in 1785

10. Sky Safari: Andromeda by Kochava Yerushalmit
Sky Safari – A Slooh Production by Kochava Yerushalmit