BL Lac object

Related to BL Lac object: abl, Blazar, Seyfert galaxy, ACBL

BL Lac object

(Celestial Objects) an extremely compact violently variable form of active galaxy

[C20: named after BL Lacertae, first identified example found in the constellation Lacerta and originally thought to be a variable star]

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Mentioned in ?

blazar

References in periodicals archive ?

Pan, "Optical photometry of the BL Lac object 1ES1959+650," The Astronomical Journal, vol.

Long-Term Optical and Spectral Variability of FSRQ 3C454.3

Finally, turning to his home soil of the Variable Star Section (VSS), the President congratulated Gary Poyner upon his fine observations of the BL Lac object OJ 287, made as a part of the VSS's observing campaign for the object.

Annual general meeting, 2008 October 29: held at the royal astronomical society, Burlington house, Piccadilly, London WI

Weekes notes that the gamma radiation generated by Markarian 421 probably comes from the edges of a jet believed to emanate from a quasar-like entity, called a BL Lac object, at the galaxy's center.

Energetic gammas from beyond the galaxy

As a result of foreshortening and the proximity of the brilliant nucleus, any optical jet would be extremely difficult to detect in a BL Lac object. And, indeed, only one of the 40 or so BL Lacs studied in detail had ever been observed with such a feature.