Back Delta Cephei Afrikaans دلتا قيفاوس Arabic Delta Cephei AST Delta Cephei BS Delta Cephei Catalan Delta Cephei Czech Delta Cephei German Delta Cephei Spanish Delta Cephei Basque دلتا قیفاووس Persian
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cepheus |
| δ Cep A | |
| Right ascension | 22h 29m 10.26502s[1] |
| Declination | +58° 24′ 54.7139″[1] |
| Apparent magnitude (V) | 4.07 (3.48–4.37) / 7.5 |
| δ Cep C | |
| Right ascension | 22h 29m 09.248s[1] |
| Declination | +58° 24′ 14.76″[1] |
| Apparent magnitude (V) | 6.3 |
| Characteristics | |
| Spectral type | F5Ib-G1Ib[2] + B7-8[3] |
| U−B color index | 0.36 |
| B−V color index | 0.60 |
| Variable type | Cepheid |
| Astrometry | |
| Radial velocity (Rv) | -16.8[4] km/s |
| Proper motion (μ) | RA: +15.35[1] mas/yr Dec.: +3.52[1] mas/yr |
| Parallax (π) | 3.66+0.09 −0.10 mas[5] |
| Distance | 887 ± 26 ly (272 ± 8[6][7] pc) |
| Absolute magnitude (MV) | –3.47 ± 0.10 (–3.94 - –3.05)[6] |
| Details | |
| δ Cep A | |
| Mass | 5.26+1.26 −1.4[5] M☉ |
| Radius | 46.1+1.9 −2.1[8] R☉ |
| Luminosity | 1,949±107[9] L☉ |
| Surface gravity (log g) | 1.65[8] cgs |
| Temperature | 5,905±29[9] K |
| Metallicity [Fe/H] | +0.08[10] dex |
| Rotational velocity (v sin i) | 9[11] km/s |
| δ Cep B | |
| Mass | 0.72±0.11[5] M☉ |
| δ Cep C | |
| Luminosity | 500 L☉ |
| Temperature | 8,800[12] K |
| Orbit[5] | |
| Primary | δ Cep A |
| Companion | δ Cep B |
| Period (P) | 9.32+0.03 −0.04 yr |
| Semi-major axis (a) | 0.029+0.002 −0.003″ |
| Eccentricity (e) | 0.71±0.02 |
| Inclination (i) | 124+17 −12° |
| Longitude of the node (Ω) | 78+56 −50° |
| Periastron epoch (T) | 1982.294+0.111 −0.101 yr |
| Argument of periastron (ω) (secondary) | 230+4 −3° |
| Semi-amplitude (K1) (primary) | 1.509 ± 0.2[4] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Delta Cephei (δ Cep, δ Cephei) is a quadruple star system[4] located approximately 887 light-years away in the northern constellation of Cepheus, the King. At this distance, the visual magnitude of the star is diminished by 0.23 as a result of extinction caused by gas and dust along the line of sight.[6] It is the prototype of the Cepheid variable stars that undergo periodic changes in luminosity.
- ^ a b c d e f Cite error: The named reference
aaa474_2_653was invoked but never defined (see the help page). - ^ Cite error: The named reference
englewas invoked but never defined (see the help page). - ^ Cite error: The named reference
evanswas invoked but never defined (see the help page). - ^ a b c Cite error: The named reference
anderson15was invoked but never defined (see the help page). - ^ a b c d Cite error: The named reference
Nardettowas invoked but never defined (see the help page). - ^ a b c Cite error: The named reference
benedict02was invoked but never defined (see the help page). - ^ Cite error: The named reference
majaess2012was invoked but never defined (see the help page). - ^ a b Cite error: The named reference
baineswas invoked but never defined (see the help page). - ^ a b Cite error: The named reference
gallennewas invoked but never defined (see the help page). - ^ Cite error: The named reference
aaa488_1_25was invoked but never defined (see the help page). - ^ Cite error: The named reference
ciako1970was invoked but never defined (see the help page). - ^ Cite error: The named reference
apj744_1_53was invoked but never defined (see the help page).