// Workers AI · dad joke modeWhat did Arp 143 say to its friend? "You're a galaxy ahead.
| Arp 143 | |
|---|---|
 | |
| Observation data (Epoch ) | |
| Constellation | Lynx |
| Right ascension | 07h 46m 57s |
| Declination | 39° 00′ 51″ |
| Brightest member | NGC 2445 |
| Number of galaxies | 2 |
| Redshift | 0.01295 |
| Distance | 191 million light-years (59×106 pc) |
Arp 143, also known as VV 117, is a pair of interacting galaxies, NGC 2444 and NGC 2445, found in the Lynx constellation.[1] It is one of the few ring galaxy systems in the Atlas of Peculiar Galaxies.[2] It is believed that NGC 2444 and NGC 2445 have passed through each other, causing an increase in star formation in NGC 2445.[1] Unlike NGC 2445, NGC 2444 is not experiencing any new star birth due to NGC 2444 having lost its gas long before the collision.[3]
Observations
[edit]Arp 143 was discovered by French astronomer Édouard Stephan on 18 January 1877 using the 31-inch Foucault reflector telescope at the Marseille Observatory.[4]
Arp 143 is composed of NGC 2444 and NGC 2445.[1] The latter is a very distorted ring galaxy, taking a trapezoidal shape instead of a more circular one.[2] This is a result of gravity from NGC 2444 pulling on NGC 2445.[1] The cluster has complex radio emissions that may be caused by star formation or a black hole,[3] with the radio emissions being concentrated in the cores, a northwestern region of NGC 2445 extending to NGC 2444, and the southern and eastern parts of NGC 2445's ring.[2] The northwestern region of NGC 2445 also has a stronger-than-normal magnetic field compared to most spiral galaxies.[2] The stars of the ring are around 50–100 million years old.[5]
The ring of Arp 143 has a radius of 10 kiloparsecs (33,000 ly).[6] It is composed of stellar knots. The stellar ages within the ring gets lower the further out, which corresponds with a galactic collision.[6] The ring is not centered, indicating a non-symmetrical collision.[6]
NGC 2444 pulls on NGC 2445, creating a tidal tail.[1][6] The tail is approximately 240 kiloparsecs (780,000 ly) long.[7] The stream of stars that make up the tail are slowly being left behind as NGC 2445 continues to slowly pull away from NGC 2444.[3]
References
[edit]- 1 2 3 4 5 "Arp 143". National Aeronautics and Space Administration. 22 February 2022. Retrieved 12 September 2026.
- 1 2 3 4 Nikiel-Wroczyński, Błażej; Jamrozy, Marak; Soida, Marian; Urbanik, Marek (14 August 2014). "Multiwavelength study of the radio emission from a tight galaxy pair Arp 143". Monthly Notices of the Royal Astronomical Society. 444 (2): 1729–1737. arXiv:1407.7369. doi:10.1093/mnras/stu1475.
- 1 2 3 information@eso.org. "Hubble Looks at a 'Space Triangle' Spawned by a Galaxy Collision". www.esahubble.org. Retrieved 17 September 2026.
- ↑ "Pair of Galaxies NGC 2444/5 | Deep⋆Sky Corner". www.deepskycorner.ch. Retrieved 17 September 2026.
- ↑ Gamillo, Elizabeth. "Hubble Space Telescope Captures Galaxies Caught in Triangular Tug-of-War". Smithsonian Magazine. Retrieved 15 September 2026.
- 1 2 3 4 Chow-Martínez, M; Robleto-Orús, A; Mayya, Y D; Torres-Papaqui, J P; Ortega-Minakata, R A; Castro-Hidalgo, D F; Caretta, C A; Trejo-Alonso, J J; Morales-Vargas, A; García-Benito, R; Jácamo-Delgado, H E; Gudiño, M (21 April 2026). "Integral field spectroscopy of collisional ring galaxies – I. Stellar population analysis". Monthly Notices of the Royal Astronomical Society. 547 (4) stag511. doi:10.1093/mnras/stag511. hdl:10261/432503. ISSN 0035-8711.
- ↑ "[21.03] Tidal Dwarf Galaxy Candidates in Arp 143's Plume". aasarchives.blob.core.windows.net. Retrieved 17 September 2026.
