NGC 2535
Interacting unbarred spiral galaxy in Cancer with warped disk.
NGC 2535 is an unbarred spiral galaxy in the constellation Cancer. It is notable for its interaction with the companion galaxy NGC 2536, which has warped its disk and spiral arms, producing an elongated structure rich in bright, recently formed blue star clusters. The pair is listed together as Arp 82 in the Atlas of Peculiar Galaxies.
Quick Facts
- Epoch
- J2000
- Ra
- 8 · 11 · 13.4880
- Dec
- +25 · 12 · 24.739
- Z
- 4097 ± 9 km/s
- Appmag V
- 16.9
- Constellation Name
- Cancer
Facts from the source article.
Lore & Background
NGC 2535 exhibits a weak inner ring structure around its nucleus. The gravitational interaction with NGC 2536 has warped the galaxy's disk and spiral arms, creating an elongated structure visible at ultraviolet wavelengths. This structure contains many bright, recently formed blue star clusters and enhanced star-forming regions around the galaxy center. The two galaxies are cataloged together as Arp 82 in the Atlas of Peculiar Galaxies, described as an example of a spiral galaxy with a high surface brightness companion. One supernova, SN 1901A, has been observed in NGC 2535. It was first recorded on a photographic plate taken on 10 January 1901 by Karl Reinmuth, though the discovery was not made until 28 September 1923. The supernova's type remains unknown, and its apparent magnitude was 14.7.
Reader's Guide
NGC 2535 holds significance as a clear example of galactic interaction and its effects on star formation. The warped disk and elongated ultraviolet structure, populated with young blue star clusters, demonstrate how tidal forces from a companion can trigger bursts of stellar birth. Its inclusion in the Atlas of Peculiar Galaxies as Arp 82 highlights its value as a case study of a spiral galaxy paired with a high-surface-brightness companion. The distance to NGC 2535 is uncertain: its Hubble distance, based on cosmic microwave background velocity, is about 63.6 Mpc, but nine non-redshift measurements yield a much closer mean distance of roughly 27.1 Mpc. This discrepancy underscores the challenges in measuring extragalactic distances. The supernova SN 1901A, discovered years after its photographic capture, adds a historical dimension, though its type remains unknown. The galaxy's legacy lies in its role in illustrating how interactions reshape galaxies and enhance star formation, providing observational data for models of galactic evolution.
Did You Know?
- NGC 2535 was discovered on 22 January 1877 by French astronomer Édouard Stephan.
- It is interacting with NGC 2536, and the pair is listed as Arp 82 in the Atlas of Peculiar Galaxies.
- The galaxy's disk and spiral arms are warped, producing an elongated structure with many bright blue star clusters.
- Supernova SN 1901A was first recorded on a plate taken 10 January 1901 but not discovered until 28 September 1923.
Frequently Asked Questions
What is NGC 2535?
NGC 2535 is an unbarred spiral galaxy located in the constellation Cancer. It is best known for its ongoing gravitational interaction with the nearby companion galaxy NGC 2536, which has distorted its disk and spiral structure.
Who discovered NGC 2535 and when?
Édouard Stephan first catalogued the galaxy on 22 January 1877. It has since been recognized as a striking example of a galaxy whose shape has been altered by a close encounter with a neighbor.
What makes NGC 2535 look so distorted?
The companion galaxy NGC 2536 has tugged on NGC 2535's disk and arms through tidal forces, warping them into an elongated, irregular shape. This interaction has also triggered intense star formation, filling the galaxy with bright, young blue star clusters.
What is the Arp 82 designation?
Arp 82 is the catalog number assigned to the NGC 2535–NGC 2536 pair in Halton Arp's Atlas of Peculiar Galaxies. The listing highlights the pair as a visually distinctive example of gravitational interaction between two spiral systems.
How far away is NGC 2535?
Redshift-based estimates place it at roughly 63.6 megaparsecs (about 207 million light-years) from us, with an uncertainty of about 4.5 Mpc. Independent non-redshift distance measurements give a somewhat closer value near 27 megaparsecs, reflecting the well-known tension between these two methods.
More in NGC Objects, Part 4 1-24
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