Quasar 3C 66A


The radio source 3C 66 was discovered in 1959 during a survey with the Cambridge Four-Element Interferometer. The designation «3C» refers to the «Third Cambridge Catalogue of Radio Sources». Later, it was found that 3C 66 consists of two radio sources. The main source, 3C 66B, was identified with an elliptical galaxy, which later received the designation UGC 1841. The second radio source, 3C 66A, appeared to have no physical connection. It turned out to be not a star in our Milky Way but exhibiting a quasi-stellar object (QSO) spectrum. [662]

Physical Properties

3C 66A is a blazar, one of the most extreme subclasses of active galactic nuclei, whose relativistic jet is oriented towards our line of sight and emits radiation across the entire electromagnetic spectrum from radio to gamma rays. It belongs to the BL-Lac blazar class and exhibits non-periodic fluctuations in brightness that can occur within hours. Therefore, it must be a very compact object roughly the size of our solar system.

Data from Simbad [145]
Designations 3C 66A, QSO J0222+4302
Right Ascension (J2000.0) 02 22 39.6
Declination (J2000.0) +43 02 7.8
Magnitudes B 15.71; V 15.21; g 15.605; R 14.5; r 15.112; J 12.635; H 11.88; K 11.151
Redshift z 0.34

Data for the three nearby galaxies in the 15' Closeup:

«Catalogue of Principal Galaxies» Paturel et al., 1989 [144]
PGC RA Dec Type Dim Btot HRV PA Names
PGC 9029 02 22 31.2 +43 03 53 S 1.1 x .5 15.3 163 UGC 1832, MCG 7-5-45, CGCG 538-53
PGC 9051 02 22 58.4 +43 00 43 L 1.2 x .9 14.9 6385 25 UGC 1837, MCG 7-6-1, CGCG 538-55, CGCG 539-1
PGC 9067 02 23 11.5 +42 59 30 C M 3.0 x 3.0 14.6 6226 UGC 1841, MCG 7-6-3, CGCG 538-57, CGCG 539-3, 5ZW 230, ANON 220+42

Finder Chart

To locate the quasar 3C 66A, follow these instructions: About 40 arcminutes north of the galaxy NGC 891, there is a rhomboid of four stars, within which the galaxy UGC 1841 is embedded. UGC 1837 is outside the rhomboid and hangs next to the corner star towards the quasar. Parallel to the north of the rhomboid, there are two faint stars which act as the first pointer to the quasar. The three faint stars next to UGC 1832 serve as the second pointer to the quasar. The quasar 3C 66A is located at the intersection point of these two lines. The constellation Andromeda is highest in the sky at night from June to February.

Finder Chart Quasar 3C 66A
Quasar 3C 66A in constellation Andromeda. Charts created using SkySafari 6 Pro and STScI Digitized Sky Survey. Limiting magnitudes: Constellation chart ~6.5 mag, DSS2 close-ups ~20 mag. [149, 160]

Visual Observation

300 mm Aperture: The quasar 3C 66A appears as a small dot, which is roughly as bright as the faintest of the three pointer stars. The quasar is said to be variable, and based on its current brightness, it appears to be closer to its maximum brightness. — 300 mm f/5 Hofheim Dobsonian, TV-Nagler-Zoom 6mm-3mm / 250x-500x / 0.22°-0.11°, Edelweissspitze 2571m ASL, 7. 10. 2007, SQM 21.53, Eduard von Bergen

Objects Within a Radius of 15°