Planetary Nebula Longmore-Tritton 5

LoTR 5
LoTR 5: Left: Coma galaxy cluster, below: PN LoTR 5, right: galaxy NGC 4725; Technosky 60 mm f/6, 0.8 Reducer (f=288mm), ASI 2600 MC Pro, Skywatcher EQ6R pro; 153 frames, 300s, Gain 300, -10 °C; CLS filter; Oberbaselbiet; © 10.+12. April 2004 Jörg Studer


This planetary nebula was discovered 1980 by A. J. Longmore and S. B. Tritton on photo plates made with the 1.2 m UK Schmidt Telescope in New South Wales, Australia. It was listed as fifth in a list of 11 newly discovered nebulae and is hence referred to as Longmore-Tritton 5 or short: LoTr 5. They described it as «a very large and very faint non-uniform disk, slightly brighter towards the centre. Two members of a distant group or cluster of galaxies can be seen trough the nebula.» [651]

Physical Properties

LoTr 5 is located just 1.5° ways from the north galactic pole and therefore the planetary nebula with the highest galactic latitude. Modelling shows that is expanding asymmetrically and shows some form of bipolar structure with the axis inclined around 17° to the line of sight.

The central star IN Comae Berenices (SAO 82570, HD 112313, BD +26°2405) has a visual magnitude of 8.88 mag and is a fast-rotating G5 giant of luminosity class III-IV with a rotational period of 5.9 days. A long-term brightness variation with a period of ~7.2 years results from an orbiting low mass M5 companion star. [652, 653] Gaia DR3 distance is 455 pc. [145]

«Strasbourg-ESO Catalogue of Galactic Planetary Nebulae» Acker et al., 1992 [141]
Designations PN G339.9+88.4: LoTr 5, PK
Right Ascension (J2000.0) 12h 55m 34s d
Declination (J2000.0) +25° 53' 28" d
Dimensions 525." (optical)
Distance 0.40 kpc
Expansion Velocity 27. (O-III) km/s
C-Star Designations AG 26 1312, AG82 149, BD 26 2405, HD 112313, IN Com, SAO 82570
C-Star Magnitude V: 14.9
C-Star Spectral Type sdO + G5 III
Discoverer LONGMORE et al 1980

Finder Chart

The planetary Nebula LoTr 5 is located in the constellation Coma Berenices. The best observation time is December to July, when it is highest at night.

Finder Chart Planetary Nebula Longmore-Tritton 5
Planetary Nebula Longmore-Tritton 5 in constellation Coma Berenices. Charts created using SkySafari 6 Pro and STScI Digitized Sky Survey. Limiting magnitudes: Constellation chart ~6.5 mag, DSS2 close-ups ~20 mag. [149, 160]

Objects Within a Radius of 15°


  • [141] Strasbourg-ESO Catalogue of Galactic Planetary Nebulae; A. Acker, F. Ochsenbein, B. Stenholm, R. Tylenda, J. Marcout, C. Schohn; European Southern Observatory; ISBN 3-923524-41-2 (1992);;
  • [145] SIMBAD astronomical database;
  • [149] SkySafari 6 Pro, Simulation Curriculum;
  • [160] The STScI Digitized Sky Survey;
  • [651] «A second list of new planetary nebulae found on United Kingdom 1.2-m Schmidt telescope plates» A. J. Longmore, S. B. Tritton; Monthly Notices of the Royal Astronomical Society, Volume 193, Issue 3, December 1980, Pages 521–524; DOI:10.1093/mnras/193.3.521
  • [652] «Surface magnetic activity of the fast-rotating G5 giant IN Comae, central star of the faint planetary nebula LoTr 5» Zs. Kővári, K. G. Strassmeier, K. Oláh, L. Kriskovics, K. Vida, T. A. Carroll, T. Granzer, I. Ilyin, J. Jurcsik, E. Kővári and M. Weber; A&A Volume 624, April 2019; DOI:10.1051/0004-6361/201834810
  • [653] «The bipolarity of the highest Galactic latitude planetary nebula, LoTr 5 (PN G339.9+88.4), around IN Com» M. F. Graham, J. Meaburn, J. A. López, D. J. Harman, A. J. Holloway; Monthly Notices of the Royal Astronomical Society, Volume 347, Issue 4, February 2004, Pages 1370–1378; DOI:10.1111/j.1365-2966.2004.07342.x