Gliese 2

Database links to Gliese 2

Star Gliese 2
AladinLite
Observation dates equinox :  J2000.0 , epoch : J2000.0
Constellation	Andromeda
Right ascension	00 h 05 m 10.89 s
declination	+ 45 ° 47 ′ 11.7 ″
Apparent brightness	9.97 likes
Typing
B − V color index	+1.47
U − B color index	+1.18
R − I index	+1.11
Spectral class	M2 Ve
Astrometry
Radial velocity	−0.39 ± 0.09 km / s
parallax	86.96 ± 0.04  mas
distance	37.49 ± 0.02  Lj 11.5  pc
Visual absolute brightness M vis	9.63 likes
Proper movement
Rec. Share:	+870.75 ± 0.06  mas / a
Dec. portion:	−151.27 ± 0.04  mas / a
Physical Properties
radius	0.618 ± 0.027  R ☉
Effective temperature	3,484 ± 50  K
Metallicity [Fe / H]	−0.018
Rotation time	11.30 d
Other names and catalog entries
Bonn survey BD + 44 ° 4548 Gliese catalog FY 2 [1] Hipparcos catalog HIP 428 [2] Tycho catalog TYC 3246-1142-1 [3] 2MASS catalog 2MASS J00051079 + 4547116 [4] Other names G 171-39, LHS 1014, LFT 6, LTT 10011, NLTT 139, VVO 118, Vyssotsky 216, ASCC 296817, UCAC3 272-1152, As system components: ADS 48 F, CCDM J00057 + 4548 F, STT 547 F, WDS J00057 +4549 F

Gliese 2 ( BD  + 44 ° 4548, HIP  428) is a red dwarf star in the constellation Andromeda in the northern sky. It is 36.7 light years distance - about the same distance as the orange giant Arcturus - one of the nearby stars . With an apparent magnitude of 9.97 mag, it is too faint to be observed without a telescope .

Astrometry

Galactic orbit

Gliese 2 orbits the center of the Milky Way at a distance that varies between 5969 and 7922 pc, with an eccentricity of 0.141 ( major orbit half axis 6946 pc (22,655 LJ)). The current distance to the galactic center is 7405 pc (24,152 LJ), the orbital speed relative to the sun 48.1 km / s.

Its own movement in the sky, observable from earth, amounts to 0.87 ″ ( arc seconds ) annually . The radial speed is given as between 0.39 and 1.22.

distance

The most precise measurement of the parallax of 86.98 ± 1.41 mas has so far been achieved by Hipparcos . Usually the more recent, almost equally precise, but higher and probably more correct value 88.88 ± 1.42 mas is used. This results in a distance of the star to Earth of 36.696 light years (2,320,700 AU ).

Determination of the distance for Gliese 2

year	source	Parallax (mas)	Distance (pc)	Distance (Lj)	Distance ( Pm )
1970	Woolley et al.	94.00 ± 4.00	10.638   +0.47−0.43	34.697   +1.54−1.42	328.26   +14.59−13.40
1991	Gliese-Jahreiß	87.00 ± 3.80	11.49   ++ 0.52−0.48	37.49   +1.71−1.57	354.68   +16.20−14.84
1997	Hipparcos	86.98 ± 1.41	11.497   +0.19−0.18	37.498   +0.61−0.60	354.76   +5.85−5.66
1997	Tycho	64.10 ± 27.9	15.601   ++ 12.02−0.73	50.882   +339.22−15.43	481.38   +371−146
2007	van Leeuwen	88.88 ± 1.42	11.251 ± 0.18	36.696   +0.6−0.58	347.17   +5.64−5.46
2018	Gaia DR2	86.96 ± 0.04	11.50 ± 0.01	37.49 ± 0.02	354.64 ± 0.16

Non-trigonometric distance determinations are marked in italics . The most precise determination is marked in bold .

properties

Gliese 2 is a late main sequence red star . The star's spectral class has been classified from M1.0V up to M2.0V or M2.0Ve. This makes the star one of the larger objects of the class of the red dwarfs, which usually have about 40 - 60% of the solar mass and also their diameter. Gliese 2 has a radius of 0.618 solar radii , corresponding to about 860,000 km in diameter. In contrast, the metallicity of −0.018 [Fe / H] is significantly reduced compared to the sun. The surface temperature is 3'484  K , corresponding to 3'211  ° C . The star revolves once in 11.5 days.

Belonging to the ADS 48 system

Gliese 2 ("ADS 48 F") does not actually form a system as a single star. The system of (officially) seven stars known as ADS 48 consists in a narrower sense of the binary star system Gliese 4 A and B , an orange and a red dwarf star that orbit each other in a close orbit. Gliese 2 to the west of the system, which is almost 0.2 light years (around 11,500 AU) closer to our sun, belongs in the broader sense because it has a comparable proper movement and distance to the solar system . According to recent measurements, it is gravitationally not bound to the Gliese 4 system. The galactic orbit of Gliese 2 is slightly slower and more elliptical compared to the orbit of the double system. The angular distance of 328 arc seconds determined during the measurements corresponds to a distance of 3706 astronomical units to the double system at this heliocentric distance .

The other components of the ADS 48 system are background stars that are in no way related to the three stars mentioned above. The distances of these stars are so far unknown, so the values ​​for the measured visual brightness are based on an assumed equal heliocentric distance to the Gliese 4 system. ADS 48 "C" is itself a double system of two stars that are close to each other and that orbit each other at a similar distance as the two Gliese 4 stars. The components "D", "E" and "P", of which "P" is optically closest to the Gliese 4 system, are single stars. The ADS 48 system is also referred to as STT 547 (but excluding "P").

In the Washington double star catalog, the components "G", "Q", "X" and "Y" are also listed, in other sources there is an "R" component. So the whole system would have to consist of a total of 13 individual stars.

Surname	Another name	Spectral class	Coordinates	Angular distance as	Radial weakened. km / s	Own weighted RA mas / s	Own weight DA mas / s	Apparent Helligk. like
ADS 48 A Gliese 4 A	WDS J00057 + 4549 A 2MASS J00054091 + 4548435	K6.0V	00h 05m 41.013s + 45 ° 48 ′ 43.49 ″	0.00	3.50	887.48	−152.02	8.83
ADS 48 B Gliese 4 B	WDS J00057 + 4549 B 2MASS J00054090 + 4548374	M0.5V	00h 05m 40.342s + 45 ° 48 ′ 38.73 ″	6.00 (2013)	1.90	887.48	−152.02	9.00
ADS 48 Ca STT 547 C	WDS J00057 + 4549 Ca GSC 03246-01561	?	00h 05m 40.342s + 45 ° 48 ′ 38.73 ″	113.40 (2012)		0.00	0.00	13.71
ADS 48 Cb STT 547 C	WDS J00057 + 4549 Cb GSC 03246-01561	?	00h 05m 40.342s + 45 ° 48 ′ 38.73 ″	113.40 (2012)		0.00	0.00	14.90
ADS 48 D GSC + 03246-01146	WDS J00057 + 4549 D 2MASS J00053425 + 4547303	?	00h 05m 34.248s + 45 ° 47 ′ 30.27 ″	108.40 (2012)		2.90	−0.20	12.53
ADS 48 E GSC + 03246-01100	WDS J00057 + 4549 E 2MASS J00054081 + 4549374	?	00h 05m 40.819s + 45 ° 49 ′ 37.42 ″	57.50 (2013)		8.00	−8.90	11.68
ADS 48 F Gliese 2	WDS J00057 + 4549 F 2MASS J00051079 + 4547116	M2.0Ve	00h 05m 10.889s + 45 ° 47 ′ 11.65 ″	327.90 (2007)	−0.39	870.19	−150.45	9.97
ADS 48 P POP 217 P	WDS J00057 + 4549 P GSC + 03246-00320	?	00h 05m 41.432s + 45 ° 48 ′ 52.44 ″	13.10 (2013)		0.10	3.90	13.00

Individual evidence

1. ↑ ^{a b c d e f} BD + 44 4548. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed August 26, 2018 . 
2. ^ ^{A b} van Leeuwen F. (2007): HIP 428. Accessed July 1, 2015 . 
3. ↑ Mermilliod J.-C (1986): Eggen's UBV data. Retrieved July 1, 2015 . 
4. ↑ ^{a b c d e} Houdebine (2010): GJ 2. Accessed July 1, 2015 . 
5. ↑ Nidever (2002): GJ 2. Retrieved on July 1, 2015 . 
6. ↑ ^{a b} Gliese, W .; Jahreiß, H. (1991): Gliese 2. Accessed July 1, 2015 . 
7. ↑ Ashland Astronomy Studio: Gliese 2 (HIP 428). (No longer available online.) Archived from the original on July 3, 2015 ; accessed on July 1, 2015 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  
8. ^ ^{A b} Dawson (2005): LHS 1014. Retrieved July 1, 2015 . 
9. ^ Woolley R. et al .: Woolley 2. Retrieved July 1, 2015 . 
10. ↑ ^{a b} Perryman et al. (1997): HIP 428.Retrieved July 1, 2015 . 
11. ↑ Perryman et al .: TYC 3246 1142 1. Retrieved July 1, 2015 . 
12. ↑ The star in VizieR. In: Gaia DR2 . Center de Données astronomiques de Strasbourg , accessed August 26, 2018 . 
13. ↑ Van Altena WF et al. (1995): GCTP 4. Retrieved July 1, 2015 . 
14. ↑ Z. Cvetković et al. (2001-2014): ADS 48: Visual binary or multiple system. Retrieved July 1, 2015 . 
15. ↑ ^{a b} Mason et al. 2001-2014: WDS J00057 + 4549. Retrieved July 1, 2015 . 
16. ↑ SIMBAD: Gliese 4 A. Accessed July 1, 2015 . 
17. ↑ SIMBAD: Gliese 4 B. Accessed July 1, 2015 . 
18. ↑ Dommanget et al. (2002): CCDM J00057 + 4548 C. Accessed July 1, 2015 . 
19. ↑ SIMBAD: GSC + 03246-01146. Retrieved July 1, 2015 . 
20. ↑ SIMBAD: GSC + 03246-01146. Retrieved July 1, 2015 . 
21. ↑ SIMBAD: POP 217 P. Retrieved July 1, 2015 .