LoTr 1
 | An editor has determined that sufficient sources exist to establish the subject's notability. (August 2026) |
| Emission nebula | |
|---|---|
| Planetary nebula | |
| Observation data: J2000 epoch | |
| Right ascension | 05h 55m 06.6s |
| Declination | −22° 54′ 02″ |
| Distance | 5,875 ly |
| Apparent diameter | 2' 26" ± 4" |
| Constellation | Lepus |
| Designations | DeHt 1, PK 228-22 1, PN G228.2-22.1, AB Lep |
LoTr 1 or DeHt 1 is a bubble-shaped elliptical planetary nebula with a binary central star system. LoTr 1 was discovered with 11 other planetary nebula under the LoTr Catalog and was discovered in 1980 by astronomers A.J Longmore and S.B. Tritton using the UK Schmidt Telescope.
Characteristics
The nucleus of LoTr 1 has similar properties that can be found in other planetary nebulae (PNe) like Abell 35 and LoTr 5, LoTr 1 has a nucleus containing a giant star and a hot companion, the binary system was detected by the International Ultraviolet Explorer. The nebula features a central inner shell with an angular diameter of 47 ± 4" and a expansion age of ~17,000 years. The planetary nebula also features an outer shell with a more irregular shape that has a diameter of 4 ± 26" and an expansion age of ~35,000 years. The inner and outer shell has an expansion velocity of ~25 ± 4 km. The nebula is significantly brighter in ionized oxygen O III wavelengths compared to other emissions. The two slightly elongated shells possess different spatial orientations, this indicates that a separate historical mass-transfer or ejection episodes from the binary interaction occurred. The double-peaked Hα emission lines remain a mystery, but have been hypothesized to come from the active accretion disk.
AB Leporis
AB Leporis is a binary star system that contains a variable K-type subgiant star with an emission line and a hot white dwarf companion. The K-type giant star was found to have a barium abundance of 0.5 or greater, this classifies the K-type giant star as a barium star. The K-type giant features a rapid rotation period of 6.4 days, which proves past mass accretion activity. The star has a orbital period of ~100 and ~1,500 years and was also spun up to a rapid 6.4-day rotation via wind accretion, this occurred when the star was in the asymptotic giant branch (AGB) phase. The star system has an orbital period of ~11.28 years. The radial velocity of the binary is ~7.4 yr. The lack of observed [Fe V] lines and the absence of the [C III] multiplet imposes a temperature limit of ~105,000 K. The radius for the giant star is ~9.7R while the hot white dwarf has a radius of 0.44R, indicating that it is about to enter white dwarf cooling sequence.
References
- 1 2 3 "V* AB Lep". simbad.cds.unistra.fr.
- ↑ "Longmore Tritton 1 PN in Lepus". chart32.de.
- 1 2 3 4 5 Tyndall, A. A.; Jones, D.; Boffin, H. M. J.; Miszalski, B.; Faedi, F.; Lloyd, M.; Boumis, P.; López, J. A.; Martell, S.; Pollacco, D.; Santander-García, M. (2013-12-11). "Two rings but no fellowship: LoTr 1 and its relation to planetary nebulae possessing barium central stars". Monthly Notices of the Royal Astronomical Society. 436 (3): 2082–2095. arXiv:1309.4307. doi:10.1093/mnras/stt1713. ISSN 1365-2966.
- ↑ Longmore, A. J.; Tritton, S. B. (1980). "A second list of new planetary nebulae found on United Kingdom 1.2-m Schmidt telescope plates". Monthly Notices of the Royal Astronomical Society. 193 (3): 521–524. doi:10.1093/mnras/193.3.521. ISSN 0035-8711.
- ↑ Bond, Howard E.; Ciardullo, Robin; Meakes, Michael G. (1993). "The Abell 35-Type Planetary Nuclei". Symposium - International Astronomical Union. 155: 397. doi:10.1017/S0074180900171864. ISSN 0074-1809.
- ↑ Weinberger, R. (May 1989). "A catalogue of expansion velocities of galactic planetary nebulae". Astronomy & Astrophysics. 78 (301–324): 301. Bibcode:1989A&AS...78..301W.
- ↑ Martínez, C. I.; Mauas, P. J. D.; Buccino, A. P. (2022-05-14). "Activity cycles in RS CVn-type stars". Monthly Notices of the Royal Astronomical Society. 512 (4): 4835–4845. arXiv:2111.05911. Bibcode:2022MNRAS.512.4835M. doi:10.1093/mnras/stac755.
- ↑ Werner, K.; Reindl, N.; Löbling, L.; Pelisoli, I.; Schaffenroth, V.; Rebassa-Mansergas, A.; Irawatuli, P.; Ren, J. (October 2020). "An extremely hot white dwarf with a rapidly rotating K-type subgiant companion: UCAC2 46706450". Astronomy & Astrophysics. 642: 13. arXiv:2009.02968. Bibcode:2020A&A...642A.228W. doi:10.1051/0004-6361/202038574. A288.
- ↑ Bhattacharjee, S.; Reindl, N.; Bond, H. E.; Werner, K.; Zeimann, G. R.; Jones, D.; El-Badry, K.; Mackensen, N.; Chornay, N.; Kulkarni, S. R.; Caiazzo, I.; Roestel, J. V.; Rodriguez, A. C.; Prince, T. A.; Laher, R. R.; Rusholme, B.; Smith, R. (17 October 2025). "Variability of Central Stars of Planetary Nebulae with the Zwicky Transient Facility. II. Long-timescale Variables including Wide Binary and Late Thermal Pulse Candidates". Astronomical Society of the Pacific. 137 (10): 10. arXiv:2502.18651. Bibcode:2025PASP..137j4206B. doi:10.1088/1538-3873/ae051e.
