Triangulum

Triangulum is a small yet ancient northern constellation, nestling between Andromeda and Aries. It appears highest in the evening sky in the months around October.

Comprising simply of a triangle of two third magnitude stars and one fourth magnitude star, it is far from conspicuous. In ancient Greece it was known as ‘Deltoton’ because it resembled a capital delta (Δ).

Although it is home to only one bright deep sky object, it is a significant one. The Triangulum Galaxy (M33) is a member of the Local Group of galaxies, and the second-closest galaxy of comparable size to our own.

M33 is a spiral galaxy like our own, and orientated in an almost face-on orientation so that its spiral structure is finely displayed. However, this also means its light is spread over a large sky area, comparable in size to the full moon. The slightest light pollution makes it quite impossible to make out its diffuse light.

In the Babylonian star catalogues, Triangulum, together with Gamma Andromedae, formed the constellation that represented a Plough.

The Indian astronomy system calls Triangulum by the native name ತ್ರಿಕೋನಿ (Trikoni).

Triangulum contains:

 

• Stars
  • β-Tri (mag 3.0)
  • Mothallah (mag 3.4)
  • γ-Tri (mag 4.0)
  • δ-Tri (mag 4.9)
  • 14-Tri (mag 5.2)
  • HD (mag 5.2)
  • 7-Tri (mag 5.2)
  • 10-Tri (mag 5.3)
  • 12-Tri (mag 5.3)
  • 15-Tri (mag 5.4)
  • ε-Tri (mag 5.5)
  • 11-Tri (mag 5.6)
  • HD 10390 (mag 5.6)
  • HD 11007 (mag 5.8)
  • HD 15755 (mag 5.8)
  • HD 11928 (mag 5.9)
  • 13-Tri (mag 5.9)
  • HD 10348 (mag 6.0)
  • HD 16187 (mag 6.1)
  • 5-Tri (mag 6.2)
  • HD 16220 (mag 6.2)
  • HD 15464 (mag 6.3)
  • HD 10588 (mag 6.3)
  • HD 9298 (mag 6.4)
  • HD 14373 (mag 6.5)
• Open Clusters
  • IC 1800
  • None
• Globular Clusters
  • None
• Galaxy
  • Messier 33 (mag 5.7)
  • NGC 925 (mag 10.1)
  • NGC 672 (mag 11.1)
  • NGC 777 (mag 11.4)
  • NGC 890 (mag 11.6)
  • NGC 1060 (mag 11.8)
  • NGC 949 (mag 12.0)
  • IC 1727 (mag 12.0)
  • NGC 784 (mag 12.1)
  • NGC 736 (mag 12.2)
  • NGC 750 (mag 12.2)
  • NGC 959 (mag 12.4)
  • NGC 969 (mag 12.4)
  • NGC 751 (mag 12.5)
  • NGC 670 (mag 12.7)
  • NGC 855 (mag 12.8)
  • NGC 783 (mag 12.8)
  • NGC 669 (mag 12.9)
  • NGC 661 (mag 13.0)
  • NGC 684 (mag 13.2)
  • IC 1784 (mag 13.2)
  • NGC 688 (mag 13.3)
  • NGC 940 (mag 13.4)
  • NGC 987 (mag 13.4)
  • NGC 769 (mag 13.4)