NGC 1931 - 30.3.2021 at 23.00 - 30.3.2021 at 23.30 Janakkala, Tervakoski Observation number 97232

• Observation target
• • Deep space object
• Designation
• • NGC 1931
• Constellation
• • Auriga
• Darkness
• • Excellent

• Seeing
• • Excellent
• Nebulae
• • Emission nebula

    In an emission nebula the hot stars nearby cause the gas glow. This should not mix with reflection nebula, where the gas is only lit up by nearby stars.

    The appearance of a gas nebula is irregular, and the fainter parts of it need bigger instruments to be visible.

     

    

    Emssion nebulae in Cepheus. The bigger part is composed of the nebulae Cederblad 214 (Ced214) and NGC 7822. The lower round nebula is called Sharpless 170 (Sh2-170). Image J-P Metsävainio.

     

    

    The Orion nebula. Image Samuli Vuorinen.

     

    

    In this 4-degree-field there are emission nebulae Sh2-157, Sh2-158, Sh2-159, Sh2-161 and Sh2-162 (or NGC 7635 aka Bubble Nebula) and open clusters M52 and NGC 7510. Image Juha Kepsu.

     

    

    NGC 281 aka Pacman Nebula. The object is in Cassiopeia. Image J-P Metsävainio.

     

    

    NGC 896 in Cassiopeia is the tip of Heart Nebula (IC 1805). Image Timo Inkinen.

  • Reflection nebula

    Reflection nebula is gas only lit up by nearby stars. It should not be mix up with emission nebula, where hot stars nearby cause the gas glow. But then reflection nebulae are visible in the same areas with emission nebulae. The appearance of reflection nebulae is irregular, and many of them need bigger instruments to be visible.

     

    

    Reflection nebulae are glowing blue around the stars of Pleyades. Image Juha Parvio.

     

    

    The blue glowing reflection nebula NGC 1333 around the bright star is in Perseus. Image Timo Inkinen.

     

    

    The bluish reflection nebula NGC 2023 is located lower left from the Horsehead Nebula. The Horsehead Nebula itself is a dark nebula in the front of red emission nebula IC 434. In the left side there is NGC 2024 aka Flame Nebula. Image Samuli Vuorinen.

     

    

    NGC 7538 in Cepheus is a combination of reflection and emission nebula. Image Timo Inkinen.

     

    

    Rflection nebulae (LBN 550, 552 and 555) and dark nebulae (LDN 1228) in Cepheus. Image Juha Kepsu.

     

    

    Reclection nebula vdB 141 in Cepheus. Image Tero Turunen.

eVscope exposure 30min