|Observation data (Epoch J2000)|
|Right ascension||0h 26m 35s|
|Declination||+17° 9′ 43″|
Cl 0024+17 is allowing astronomers to probe the distribution of dark matter in space. The blue streaks near the center of the image are the smeared images of very distant galaxies that are not part of the cluster. The distant galaxies appear distorted because their light is being bent and magnified by the powerful gravity of Cl 0024+17, an effect called gravitational lensing.
Dark matter cannot be seen because it does not shine or reflect light. Astronomers can only detect its influence by how its gravity affects light. By mapping the distorted light created by gravitational lensing, astronomers can trace how dark matter is distributed in the cluster. While mapping the dark matter, astronomers found a dark-matter ring near the cluster's center (although this is disputed by other independent studies). The ring's discovery is among the strongest evidence that dark matter exists.
- "HubbleSite NewsCenter". Results for Cl 0024+17. Retrieved 2007-05-16.
- Ponente, P.P; Diego, J.M (2011). "Systematics in lensing reconstruction: dark matter rings in the sky?". Astronomy and Astrophysics. 535: 119–130. arXiv:1110.3979. Bibcode:2011A&A...535A.119P. doi:10.1051/0004-6361/201117382. S2CID 11608104.