Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Scorpius |
Right ascension | 17h 26m 29.387s [1] |
Declination | −35° 40′ 56.20″ [1] |
Characteristics | |
Astrometry | |
Proper motion (μ) |
RA: 2.469
[1]
mas/
yr Dec.: 1.374 [1] mas/ yr |
Parallax (π) | 2.5190 ± 1.1187 mas [2] |
Distance | approx. 1,300
ly (approx. 400 pc) |
Details | |
Other designations | |
Gaia DR2 5974962995291907584
[1] | |
Database references | |
SIMBAD | data |
VVV-WIT-07 is a unique variable star which presents a sequence of recurrent dimmings (Ks~14.35 – 16.164) [1] with a possible deep eclipse in July 2012. The star, located in the Scorpius constellation about 23,000 ly (7,100 pc) away, [1] is not a binary star, which would eliminate such a system from explaining the various observed dimmings. [3]
The star was found by the " Vista Variables in the Via Lactea" (VVV) project, which is a survey of European Southern Observatory (ESO) variability of the innermost bulge of the Milky Way galaxy. The near-infrared spectra of VVV-WIT-07 appear without features, without prominent emission or absorption lines. The characteristics found in the light curve of VVV-WIT-07 (WIT refers to "What Is This?") are similar to those seen in J1407 ( Mamajek's Object), a pre-MS K5 dwarf with a ring system that eclipses the star or, alternatively, to Tabby's star, an F3 IV/V star that shows irregular and aperiodic obscurations in its light curve. [1] [4] [5] [6] [7] [8] [3]
From 2010 to 2018, the star dimmed and brightened irregularly (v~14.35 – 16.164), [1] and seemed similar to Tabby's star, except the light from VVV-WIT-07 dimmed by up to 80 percent, while Tabby's star faded by only about 20 percent. [8] Another star, J1407, however, has been found to have dimmed by up to 95%, which may be more similar to the light curve presented by VVV-WIT-07. [8] Nonetheless, according to ESO astronomer Valentin Ivanov, "A key word that could be used to describe our finding [of VVV-WIT-07] is extreme. In every aspect ... We have identified a system that challenges the imagination even more than usual, because it is so unlike our own planetary system." [3]