| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 18h 33m 57.76631s |
| Declination | −33° 00′ 59.6170″ |
| Apparent magnitude (V) | 5.28 |
| Characteristics | |
| Spectral type | B2III/IV |
| B−V color index | −0.115 |
| Variable type | SPB? |
| Astrometry | |
| Proper motion (μ) | RA: +1.691 mas/yr Dec.: −11.670 mas/yr |
| Parallax (π) | 2.7191±0.1688 mas |
| Distance | 1,200 ± 70 ly (370 ± 20 pc) |
| Absolute magnitude (MV) | −2.73 |
| Details | |
| Mass | 7.3±0.5 M☉ |
| Radius | 5.3±0.7 R☉ |
| Luminosity | 3200±700 L☉ |
| Surface gravity (log g) | 3.81±0.20 cgs |
| Temperature | 18800±900 K |
| Rotational velocity (v sin i) | 107±16 km/s |
| Other designations | |
| Alwasl, CD−33 13338, GC 25327, HD 171034, HIP 91014, HR 6960, SAO 210312, PPM 297883 | |
| Database references | |
| SIMBAD | data |
HD 171034, also named Alwasl, is a star in the constellation Sagittarius, about 1,200 light-years (370 parsecs) distant. With an apparent magnitude of 5.28, it is faintly visible to the naked eye under good viewing conditions. Its stellar classification is variously reported as B2III/IV or B2IV/V, indicating a B-type star of uncertain luminosity class. It is a possible Beta Cephei variable or slowly pulsating B-type star. A companion star at a separation of 0.25″ was first reported in 2010.
In traditional Arab astronomy, al-Waṣl (الوَصْل), meaning the joint or connection, refers to the region between two asterisms in Sagittarius representing groups of ostriches – al-Naʿām al-Wārid "the incoming ostriches" and al-Naʿām al-Ṣādir "the outgoing ostriches". The IAU Working Group on Star Names adopted the name Alwasl for this star on 13 August 2026.