Avisual bandlight curve for LO Pegasi. The main plot (adapted from Karmakaret al.[1]) shows the long-term variability. Inset plot "A" (adapted from Kiraga[2]) shows the periodic variability, and inset "B" (also adapted from Karmakaret al.[1]) shows a flare.
LO Peg is an ultrafast rotator, completing a full rotation every 10.15 hours.[16] It is classified as aBY Draconis variable that ismagnetically active and hasstar spots. The combination of non-uniform surface brightness and rotation makes it appear to vary in luminosity.[5] Up to 25.7% of the surface is covered in spots. Long term changes in periodicity suggest activity cycles, similar to thesolar cycle,[1] with periods of approximately 3 and 7.4 years.[11] The element lithium has been detected in its atmosphere, whose abundance, in combination with the star's rapid rotation, indicates this is a young star with an age of no more than a few hundred million years.[15]
^Kiraga, M. (2012), "ASAS photometry of ROSAT sources I. Periodic variable stars coincident with bright sources from ROSAT all sky survey",Acta Astronomica,62 (1): 67,arXiv:1204.3825,Bibcode:2012AcA....62...67K
^abcSavanov, I. S.; et al. (September 2016), "Photometric Observations of LO Peg in 2014-2015",Acta Astronomica,66 (3):381–390,Bibcode:2016AcA....66..381S.
^Savanov, I.; et al. (May 2019), "Activity of rapidly rotating dwarf LO Peg an [sic] giant FK Com",Contributions of the Astronomical Observatory Skalnaté Pleso,49 (2):415–419,Bibcode:2019CoSka..49..415S.
^abJeffries, R. D.; et al. (September 1994), "BD +22 4409 : a rapidly rotating, low-mass member of the Local Association",Monthly Notices of the Royal Astronomical Society,270:153–172,Bibcode:1994MNRAS.270..153J,doi:10.1093/mnras/270.1.153.
Boehm, V. A.; Rishi, A.; Harmon, R. (January 2020). "Imaging Starspots on LO Pegasi, 2014-2019".Bulletin of the American Astronomical Society.52 (1).Bibcode:2020AAS...23527304B.
Pandey, S. B.; et al. (December 2014), "Long-term spot topography and multi-band flare analysis of active ultra-fast rotator LO Peg",Proceedings of Swift: 10 Years of Discovery (SWIFT 10), held 2-5 December 2014 at La Sapienza University, Rome, Italy, p. 155,Bibcode:2014styd.confE.155P,doi:10.22323/1.233.0155.
Pandey, J. C.; et al. (August 2011), "Optical polarimetry and photometry of young sun-like star LO Peg",The Physics of Sun and Star Spots, Proceedings of the International Astronomical Union, IAU Symposium, vol. 273, pp. 455–459,Bibcode:2011IAUS..273..455P,doi:10.1017/S1743921311015766.
Harmon, R. O.; Saranathan, V. (December 2004), "Spot topography of BD+22o 4409 (LO Peg) using Matrix Light-curve Inversion",Bulletin of the American Astronomical Society,36: 1361,Bibcode:2004AAS...205.1410H.
Csorvási, R. (September 2006), Forgács-Dajka, E. (ed.), "Photometry of LO Pegasi in B, V, R colors",Proceedings of the 4th Workshop of Young Researchers in Astronomy & Astrophysics; Budapest, Hungary, 11-13 January, 2006, vol. 17, Astronomy Department of the Eötvös University (PADEU), p. 95,Bibcode:2006PADEU..17...95C.
Dal, H. A.; Tas, G. (March 2003), "New Photoelectric Photometry of the Young Star LO Pegasi",Information Bulletin on Variable Stars,5390 (1): 1,Bibcode:2003IBVS.5390....1D.
Lister, T. A.; et al. (August 1999), "Doppler imaging of BD+22° 4409 (LO Peg) using least-squares deconvolution",Monthly Notices of the Royal Astronomical Society,307 (3):685–694,Bibcode:1999MNRAS.307..685L,doi:10.1046/j.1365-8711.1999.02662.x.
Eibe, M. T.; et al. (January 1999), "Evidence for large-scale, global mass inflow and flaring on the late-type fast rotator BD+22 deg 4409",Astronomy and Astrophysics,341:527–538,Bibcode:1999A&A...341..527E.
Robb, R. M.; Cardinal, R. D. (August 1995), "Optical Observations of the Active Star RE J2131+233",Information Bulletin on Variable Stars,4221 (1): 1,Bibcode:1995IBVS.4221....1R.
