61 Leonis

{{about|p² Leonis|other stars with this Bayer designation|p Leonis}}

{{Starbox begin

| name = 61 Leonis

}}

{{Starbox observe

| epoch = J2000

| constell = Leo

| ra = {{RA|11|01|49.67462}}

| dec = {{DEC|-02|29|04.5007}}

| appmag_v = 4.73

}}

{{Starbox character

| type = AGB

| class = M0 III

| b-v = {{Val|+1.593|0.059}}

| u-b =

| variable = suspected

}}

{{Starbox astrometry

| radial_v = {{Val|−12.7|0.3}}

| prop_mo_ra = +9.76

| prop_mo_dec = −35.56

| parallax = 5.58

| p_error = 0.24

| parallax_footnote =

| absmag_v = −1.53

}}

{{Starbox detail

| source =

| mass =

| radius = 74.5

| luminosity = 1,377.86

| gravity = {{Val|1.25|0.23}}

| temperature = {{Val|3864|30|fmt=commas}}

| metal_fe = {{Val|0.07|0.07}}

| rotational_velocity =

| age_myr =

}}

{{Starbox catalog

| names = {{odlist | B=p² Leo | F=61 Leo | BD=-01°2471 | FK5=2879 | HD=95578 | HIP=53907 | HR=4299 | SAO=137947 | NSV=5059 }}

}}

{{Starbox reference

| Simbad = 61+Leo

}}

61 Leonis is a possible binary star system in the zodiac constellation of Leo. It is faintly visible to the naked eye, having an apparent visual magnitude of 4.73. The star is moving closer to the Sun with a heliocentric radial velocity of −12.7 km/s. It is located roughly 580 light-years from the Sun, as determined from its annual parallax shift of {{Val|5.58|ul=mas}}.

This is an evolved red giant star with a stellar classification of M0 III that Eggen (1992) listed as being on the asymptotic giant branch (AGB). It is a marginal barium star, showing an enhanced abundance of s-process elements in its outer atmosphere. This material may have been acquired during a previous mass transfer from a now white dwarf companion, or self-enriched by a dredge-up during the AGB process. The measured angular diameter after correctly for limb darkening is {{Val|3.87|0.04|ul=mas}}, which, at the estimated distance of this system yields a physical size of about 74.5 times the radius of the Sun.

61 Leonis is a suspected variable star with apparent magnitude changing between 4.69 and 4.79. The variability was reported in a 1966 photometric survey, but has not been confirmed by more recent photometry.

References

{{reflist|refs=

{{cite journal|bibcode=1966RGOB..122...59C|title=Fabry photometry of bright southern stars|journal=Royal Greenwich Observatory Bulletins|volume=122|pages=59|author=A. W. J. Cousins|year=1966}}

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| url=https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41 }}. The radius (R_*) is given by:

: $\begin{align} 2\cdot R_*
& = \frac{(179\cdot 3.87\cdot 10^{-3})\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\
& \approx 149\cdot R_{\bigodot}
\end{align}$

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| journal=Astronomy & Astrophysics

| volume=546 | id=A61 | pages=14 | date=October 2012