AP Librae multiwavelength SED

AP Librae is a BL Lac object at redshift z = 0.049. Its MMDC SED has 7,536 points from 50 catalogues, with dated data from 2007–⁠2025. Download the SED as CSV.

Updated 29 October 2026.

Names and position

Also known as 1FGL J1517.8-2423, 1FLAT J151741.9-242220, 1Jy 1514-241, 1OUNYU J151742-2422.3, 2FGL J1517.7-2421, 2FHL J1517.7-2421, 3FGL J1517.6-2422, 5BZB J1517-2422, ApLib, BZB J1517-2422, CRATES J151743-242216, ESO514-1, PKS 1514-241, PKS B1514-241, TXS 1514-241, WMAP205, WMAP5 J0816-2425.

Class: BL Lac
Redshift: z = 0.049
Position (ICRS): RA 229.42422°, Dec −24.37208°
Galactic: l 340.681°, b 27.578°

Other names and measurements: NED and SIMBAD within 5″ of this position.

The SED

Data: 7,536 points (3 upper limits) from 50 catalogues
Dated data: 2007–2025 (MJD 54198–60865)
Undated catalogue values: 1,048
Frequency range of detections: log ν = 7.9–26.2 [Hz] (radio, microwave, infrared, optical, ultraviolet, X-ray, γ-ray)
Swift measurements analysed by MMDC: 132 UVOT and 192 XRT
Largest catalogues (points): ASAS-SN (4,243), ALMA (855), ZTF (474), SMARTS (395), PACO (360)

Data by band

All 7 bands have data. The optical band has the most points, 4,795 of 7,536; its largest catalogue is ASAS-SN with 4,243.

Band	Points	Catalogues	Dated data
radio	65	10	undated
microwave	1,244	7	2012–2018
infrared	564	10	2010–2014
optical	4,795	5	2007–2025
ultraviolet	2	1	undated
X-ray	603	11	2007–2018
γ-ray	263	6	2008–2025

Get the data

The SED as CSV from the MMDC SED API (docs.mmdc.am).

In Python, with astro-mmdc:

from astro_mmdc import MMDC
sed = MMDC().sed.get(ra=229.42422, dec=-24.37208, name="AP Librae")

The interactive SED plot, with time filtering and modeling (needs JavaScript).

Nearby sources

RBS 1457, 9.3° away
PKS 1451-375, 14.3° away
PKS 1510-089, 15.3° away
PKS 1440-389, 16.4° away

Other BL Lac objects

How to cite

Sahakyan, N., Vardanyan, V., Giommi, P., et al. 2024, AJ, 168, 289, doi:10.3847/1538-3881/ad8231 (arXiv:2410.01207).