VdB 158 is a faint reflection nebula located in the constellation of Andromeda, at the southern tip of the elongated molecular cloud known as LBN 534 or GAL 110–13.[1][2] It is illuminated primarily by the hot B-type main-sequence star HD 222142 (B8V),[3] whose reflected light gives the nebula its characteristic blue hue due to Rayleigh scattering.[4] The nebula appears as a small, sharply bent structure embedded within the darker filament of GAL 110–13, often described as resembling a cosmic checkmark in wide-field images.[5]
Observation
VdB 158 lies approximately 2° north of the bright star Lambda Andromedae, near the border between Andromeda and Cassiopeia.[6] Centered on HD 222142, though the associated cloud extends over about 1.5°–2° of sky in a northeast–southwest orientation.[7] The region is part of the broader Lacerta OB1 star-forming association, several degrees to the west, and is best observed from the Northern Hemisphere during late autumn and winter under dark skies.[8][9][10]
Due to its low surface brightness, VdB 158 is challenging for visual observation and requires long-exposure astrophotography to capture its details, often revealing the surrounding dark cloud and nearby objects such as the small planetary nebula PK 110–12.1 (discovered by Luboš Kohoutek in 1963).[11]
Structure
VdB 158 forms the brighter, reflective portion at the end of GAL 110–13, an isolated, cometary-shaped molecular cloud roughly 36 light-years (11 parsecs) across and elongated along a position angle pointing toward the O-type star 10 Lacertae (in Lac OB1b).[12][13] The cloud's unusual 90-degree bend and overall morphology may result from interactions such as cloud–cloud collisions, stellar winds from nearby massive stars, or the aftermath of a supernova explosion within Lac OB1, which could have triggered star formation in the region.[6] Additional illumination comes from two other B-type stars of spectral class B9V, HD 222046[14] and HD 222086,[15] which share proper motion with HD 222142, suggesting they form a small physical group embedded in the cloud.[6]
The cloud's magnetic field geometry, studied via polarimetric observations of background stars, shows a predominantly toroidal structure aligned with the cloud's long axis, consistent with compression by external radiation or shocks from 10 Lacertae at a projected distance of about 11 parsecs.[12]
References
- ↑ "vdB 158". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=vdB+158.
- ↑ "LBN 534 and vdB 158 in Andromeda - astrojolo" (in en-US). 2026-01-13. https://astrojolo.com/astrophotography/other-nebulae/lbn-534-and-vdb-158-in-andromeda/.
- ↑ "HD 222142". https://simbad.cds.unistra.fr/mobile/object.html?object_name=HD%20222142.
- ↑ "Gal 110-13 & vdb158". http://bf-astro.com/vdb158/vdb158.htm.
- ↑ Linda (2025-11-18). "(Part of the) Cosmic Checkmark and VdB 158" (in en). https://lindasastronomyadventures.space/2025/11/18/part-of-the-cosmic-checkmark-and-vdb-158/.
- ↑ 6.0 6.1 6.2 "VdB 158, LBN 534". https://www.irida-observatory.org/CCD/VdB158/VdB158.html.
- ↑ "LBN 534 and vdB 158". https://www.jthommes.com/Astro/LBN534-vdB158.htm.
- ↑ "Astrophotography by Leonardo Orazi - Photo Gallery - Nebulae - GAL 110-13 and vdB 158". https://starkeeper.it/VdB158.htm.
- ↑ van den Bergh, S. (December 1966). "A study of reflection nebulae.". The Astronomical Journal 71: 990. doi:10.1086/109995. Bibcode: 1966AJ.....71..990V. http://adsabs.harvard.edu/cgi-bin/bib_query?1966AJ.....71..990V.
- ↑ Odenwald, Sten; Fischer, Jacqueline; Lockman, Felix J.; Stemwedel, Sally (September 1992). "The unusual cometary star-forming region G110-13" (in en). The Astrophysical Journal 397: 174. doi:10.1086/171777. ISSN 0004-637X. http://adsabs.harvard.edu/doi/10.1086/171777.
- ↑ "Distant Lights - vdB 158". http://www.distant-lights.at/vdb158-2013_08_11.htm.
- ↑ 12.0 12.1 Neha, S.; Maheswar, G.; Soam, A.; Lee, C. W.; Tej, A. (2016-04-01). "Magnetic field geometry of an unusual cometary cloud Gal 110-13" (in en). Astronomy & Astrophysics 588: A45. doi:10.1051/0004-6361/201526845. ISSN 0004-6361. https://www.aanda.org/articles/aa/abs/2016/04/aa26845-15/aa26845-15.html.
- ↑ "Spaceimages - Astrofotografie by Jens Zippel". https://www.spaceimages.de/en/astrophotos/nebula/vdb-158.
- ↑ "HD 222046". https://simbad.cds.unistra.fr/mobile/object.html?object_name=HD%20222046.
- ↑ "HD 222086". https://simbad.cds.unistra.fr/mobile/object.html?object_name=HD%20222086.
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