NR Canis Majoris is a binary star[11] system in the southern constellation of Canis Major, located to the east of Sirius and Gamma Canis Majoris near the constellation border with Puppis. It has a yellow-white hue and is dimly visible to the naked eye with a combined apparent visual magnitude that fluctuates around 5.60.[3] It is located at a distance of approximately 297 light years from the Sun based on parallax.[2] The system is drifting closer to the Sun with a radial velocity of −29 km/s,[3] and in about three million years it is predicted to approach within 14.1+4.7
−4.0 ly.[12] At that time, the star will become the brightest in the night sky, potentially reaching magnitude −0.88.[13]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Canis Major |
Right ascension | 07h 27m 07.99012s[2] |
Declination | −17° 51′ 53.5058″[2] |
Apparent magnitude (V) | 5.60[3] (5.66 + 9.23)[4] |
Characteristics | |
Spectral type | F2V[5] |
B−V color index | +0.314±0.002[3] |
Variable type | δ Sct[6] |
Astrometry | |
Radial velocity (Rv) | −29.2±2.9[3] km/s |
Proper motion (μ) | RA: −2.420[2] mas/yr Dec.: +1.388[2] mas/yr |
Parallax (π) | 10.9688 ± 0.0917 mas[2] |
Distance | 297 ± 2 ly (91.2 ± 0.8 pc) |
Absolute magnitude (MV) | 0.78[3] |
Details | |
A | |
Mass | 1.62[7] or 2.18±0.04[8] M☉ |
Radius | 3.90+0.18 −0.24[2] R☉ |
Luminosity | 37.4±0.4[2] L☉ |
Surface gravity (log g) | 3.65[7] cgs |
Temperature | 7,227+238 −160[2] K |
Rotational velocity (v sin i) | 185[9] km/s |
Age | 1.494[7] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
The magnitude 5.66[4] primary component is an F-type main-sequence star with a stellar classification of F2V.[5] It is a Delta Scuti variable[6] that varies by a few hundredths of a magnitude over roughly 16 hours.[14] The star is an estimated 1.5 billion years old.[7] It has a high rate of spin with a projected rotational velocity of 185 km/s, which is giving the star an equatorial bulge that is estimated to be 8% larger than the polar radius.[9]
The secondary companion is magnitude 9.23 and lies at an angular separation of 1.3″ along a position angle of 39°, as of 2005.[4]