Epsilon Serpentis
Template:Location mark Location of ε Serpentis (circled) | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Serpens |
| Right ascension | Template:RA[1] |
| Declination | Template:DEC[1] |
| Apparent magnitude (V) | +3.69[2] |
| Characteristics | |
| Spectral type | kA2hA5mA7 V[3] |
| U−B Template:Engvar | +0.12[2] |
| B−V Template:Engvar | +0.14[2] |
| Astrometry | |
| Radial velocity (Rv) | Template:Val[4] km/s |
| Proper motion (μ) | RA: +128.19[1] mas/yr Dec.: +62.16[1] mas/yr |
| Parallax (π) | 46.30±0.19 mas[1] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Absolute magnitude (MV) | +2.04[5] |
| Details | |
| Mass | Template:Val[6] Template:Solar mass |
| Radius | Template:Val[6] Template:Solar radius |
| Luminosity | Template:Val[6] Template:Solar luminosity |
| Surface gravity (log g) | 4.346[7] cgs |
| Temperature | Template:Val[7] K |
| Metallicity [Fe/H] | +0.38[7] dex |
| Rotational velocity (v sin i) | 33.1[7] km/s |
| Age | Template:Val[6] Myr |
| Metallicity [Fe/H] | {{{metal_fe2}}} dex |
| Other designations | |
| Template:Odlist[8] | |
| Database references | |
| SIMBAD | data |
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Epsilon Serpentis, Latinized from ε Serpentis, is a single,[9] white-hued star in the constellation Serpens, in its head (Serpens Caput). It is visible to the naked eye with an apparent visual magnitude of +3.69.[2] Based upon an annual parallax shift of 46.30 mas as seen from Earth,[1] it is located 70 light years from the Sun. It is moving closer to the Sun with a radial velocity of −9 km/s.[4]
This is an Am star[10] on the main-sequence with a stellar classification of kA2hA5mA7 V.[3] This notation indicates the spectrum displays the calcium K-line of an A2 star, the hydrogen lines of an A5 star, and the metal lines of an A7 star.[11] It has been examined for the presence of a magnetic field, but the detected level was not statistically significant.[12]
Epsilon Serpentis has an estimated 1.82 times the mass of the Sun and 1.78 times the Sun's radius.[6] The star is radiating 12 times the Sun's luminosity[6] from its photosphere at an effective temperature of around 7,928 K.[7] It is a candidate for an infrared excess at a wavelength of 25 μm, suggesting a circumstellar disk of dust with a temperature of Template:Val may be orbiting roughly 4.2 AU from the host star.[13] The star is around half a billion years old[6] and is spinning with a projected rotational velocity of 33.1 km/s.[7]
Etymology
Epsilon Serpentis was a member of indigenous Arabic asterism al-Nasaq al-Yamānī, "the Southern Line" of al-Nasaqān "the Two Lines".[14] along with α Ser (Unukalhai), δ Ser, δ Oph (Yed Prior), ε Oph (Yed Posterior), ζ Oph and γ Oph.[15]
According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, al-Nasaq al-Yamānī or Nasak Yamani were the title for two stars :δ Ser as Nasak Yamani I and ε Ser as Nasak Yamani II (exclude α Ser, δ Oph, ε Oph, ζ Oph and γ Oph).[16]
In Chinese, Script error: No such module "Lang". (Script error: No such module "Lang".), meaning Right Wall of Heavenly Market Enclosure, refers to an asterism which represents eleven old states in China and which marks the right borderline of the enclosure, consisting of ε Serpentis, β Herculis, γ Herculis, κ Herculis, γ Serpentis, β Serpentis, α Serpentis, δ Serpentis, δ Ophiuchi, ε Ophiuchi and ζ Ophiuchi.[17] Consequently, the Chinese name for ε Serpentis itself is Script error: No such module "Lang". (Script error: No such module "Lang"., Template:Langx), represent the state Ba (巴) (or Pa).[18][19][20]
References
- ↑ a b c d e f Cite error: Invalid
<ref>tag; no text was provided for refs namedvanLeeuwen2007 - ↑ a b c d Cite error: Invalid
<ref>tag; no text was provided for refs namedfeinstein1974 - ↑ a b Cite error: Invalid
<ref>tag; no text was provided for refs namedGray2006 - ↑ a b Cite error: Invalid
<ref>tag; no text was provided for refs nameddeBruijne2012 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedAnderson2012 - ↑ a b c d e f g Cite error: Invalid
<ref>tag; no text was provided for refs namedBoyajian2012 - ↑ a b c d e f Cite error: Invalid
<ref>tag; no text was provided for refs namedDavid2015 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedSIMBAD - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedRodriguez2015 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedAdelman1998 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedWalker2017 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedShorlin2002 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedSmith2010 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedKunitzsch2006 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedAllen1963a - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedRhoads1971 - ↑ Template:In lang 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, Template:ISBN.
- ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedAllen1963b - ↑ Template:In lang AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 24 日 Template:Webarchive
- ↑ Template:In lang English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name Template:Webarchive, Hong Kong Space Museum. Accessed on line November 23, 2010.