IC 434

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Emission nebula
IC 434

Image of IC 434 using RGB and Hα spectral filters, whereby the reddish coloration of IC 434 emerges.

Image of IC 434 using RGB and Hα spectral filters , whereby the reddish coloration of IC 434 emerges.
AladinLite
Constellation Orion
Position
equinox :  J2000.0 , epoch : J2000.0
Right ascension 05 h 41 m 00.9 s
declination -02 ° 27 ′ 14 ″
Appearance

Apparent brightness  (B-band) 11 likes 
Angular expansion 60/10 
Ionizing source
designation Sigma Orionis 
Physical data

Affiliation Milky Way 
distance  1500 ly
history

discovery Paul and Prosper Henry
Williamina Fleming
Date of discovery February 18, 1887
June 27, 1887
Catalog names
 IC  434 •  LBN 954, Sh-2 277

IC 434 is an emission nebula in the constellation Orion , through which the Horsehead Nebula , a dark cloud on the same line of sight, is backlit and thus becomes visible.

observation

Photo of an area of ​​the Orion region by William Henry Pickering from 1888. The IC 434 and the overlaid Horsehead Nebula can be seen under the left bright star in the upper third.

Edward Charles Pickering reported on the discovery by means of the then new photography in 1890, around a year after the photo was taken by his brother and the nebula was discovered on it by his colleague Williamina Fleming .

The nebula is located south of the bright star Alnitak in the Orion Belt . Due to its equatorial position, it can be observed from all inhabited areas on earth, depending on the season. Because of the weak brightness, however, it is only visible with long exposures or with medium-sized telescopes . The nebula borders the molecular cloud Orion B to the west and reaches 70 arc minutes in length but only a few arc minutes in width. Its shape resembles a long, strip-shaped blade that runs in a north-south direction. The eastern part is covered in places by a dark cloud that belongs to Orion B and is known as the Horsehead Nebula because of its characteristic shape .

features

It is an H-II region that is ionized by radiation from the Sigma Orionis star system . Information about the temperature of the emission nebula varies between 3360  K and 8000 K. A study from 1992 named a temperature of about 6000 K.

Web links

Individual evidence

  1. ↑ NASA / IPAC EXTRAGALACTIC DATABASE
  2. ↑ a b SEDS : IC 434
  3. ↑ Seligman
  4. ↑ EC Pickering: Detection of new nebulae by photography , bibcode : 1890AnHar..18..113P
  5. ↑ Pickering, EC: Nebulae discovered at the Harvard College Observatory , bibcode : 1908AnHar..60..147P
  6. ^ Kuiper, TBH: Radio observations of IC 434 . In: Astronomy and Astrophysics . 42, No. 3, September 1975, pp. 323-327. bibcode : 1975A & A .... 42..323K .
  7. ↑ Caswell, JL, Goss, WM: A 2700 MHz map of IC 434 and the surrounding Orion Region . In: Astronomy and Astrophysics . 32, May 1974, pp. 209-216. bibcode : 1974A & A .... 32..209C .
  8. ^ Louise, R., Sapin, C .: Observations of the Bright Rim of the Horsehead Nebula in Hα and [N II] . In: Astrophysical Letters . 14, 1973, p. 119. bibcode : 1973ApL .... 14..119L .
  9. ↑ Abramenkov, EA; Krymkin, VV: Observations of the diffuse gaseous nebulae Barnard Loop and IC 434 at decametric wavelengths . In: Astronomicheskii Zhurnal . 69, No. 3, June 1992, pp. 489-496. bibcode : 1992AZh .... 69..489A .

Attention: The sorting key “IC 0434” overwrites the previously used key “IC0434”.