Sagitta is a dim but distinctive constellation in the northern sky. Its name is Latin for 'arrow', not to be confused with the significantly larger constellation Sagittarius 'the archer'. It was included among the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations defined by the International Astronomical Union. Although it dates to antiquity, Sagitta has no star brighter than 3rd magnitude and has the third-smallest area of any constellation.
Epsilon Aurigae is a multiple star system in the northern constellation of Auriga, the charioteer. It is an unusual eclipsing binary system comprising an F0 supergiant and a companion which is generally accepted to be a huge dark disk orbiting an unknown object, possibly a binary system of two small B-type stars. The distance to the system is still a subject of debate, but data from the Gaia spacecraft puts its distance at around 1,350±300 light years from Earth.
Zeta Aurigae, or ζ Aurigae, is a binary star system in the northern constellation of Auriga. Based upon parallax measurements, this system is approximately 860 light-years distant from the Sun. It has a combined apparent visual magnitude of 3.75, which is bright enough to be seen with the naked eye.
Zeta Andromedae is a star system in the constellation Andromeda. It is approximately 189 light-years from Earth.
Lambda Aurigae, Latinized from λ Aurigae, is the Bayer designation for a solar analog star in the northern constellation of Auriga. It is visible to the naked eye with an apparent visual magnitude of 4.71. Based upon parallax measurements, it is approximately 40.7 light-years distant from the Earth. The star is drifting further away with a high radial velocity of +66.5 km/s, having come to within 24.4 ly (7.5 pc) some 117,300 years ago. It has a high proper motion, traversing the celestial sphere at the rate of 0.844″ per year.
Chi Aurigae, Latinized from χ Aurigae, is the Bayer designation for a binary star system in the northern constellation of Auriga. It is visible to the naked eye with an apparent visual magnitude of 4.74. The distance of Chi Aurigae is determined at 3,900 ly based on spectroscopic observations. Parallax measurements by the Hipparcos spacecraft were unsucessful because the parallax error was bigger than the value itself, while the Gaia spacecraft measured the parallax with a 22% error, giving a distance of 3590±750 ly. The brightness of the star is diminished by 1.26 in magnitude from extinction caused by intervening gas and dust.
RT Aurigae is a yellow supergiant variable star in the constellation Auriga, about 1,500 light years from Earth.
VV Cephei, also known as HD 208816, is an eclipsing binary star system located in the constellation Cepheus. It is both a B[e] star and shell star.
A debris disk, or debris disc, is a circumstellar disk of dust and debris in orbit around a star. Sometimes these disks contain prominent rings, as seen in the image of Fomalhaut on the right. Debris disks are found around stars with mature planetary systems, including at least one debris disk in orbit around an evolved neutron star. Debris disks can also be produced and maintained as the remnants of collisions between planetesimals, otherwise known as asteroids and comets.
V420 Aurigae is a high-mass star with an inferred compact companion. Closely orbiting each other every 0.8 days, they are a source of X-ray emission.
V1400 Centauri is a young, pre-main-sequence star that was eclipsed by a likely free-floating substellar object with a circumstellar disk or rings in April–May 2007. With an age around 20 million years, the star is about as massive as the Sun and is located in the constellation Centaurus at a distance of 451 light-years away from the Sun. V1400 Centauri is a member of Upper Centaurus–Lupus subgroup of the Scorpius–Centaurus association, a group of young, comoving stars close to the Sun.
VVV-WIT-07 is a unique variable star which presents a sequence of recurrent dimmings with a possible deep eclipse in July 2012. The star, located in the Scorpius constellation about 23,000 ly (7,100 pc) away, is not a binary star, which would eliminate such a system from explaining the various observed dimmings.
X1822–371, associated with the optically visible star V691 Coronae Australis, is a neutron-star X-ray binary system at a distance of approximately 2-2.5 kiloparsecs. It is known to have a high inclination of i = 82.5°± 1.5°. This source displays relatively high brightness in the optical wavelengths when compared to the X-ray, making it a prototypical Accretion Disk Coronae (ADC) source, i.e. a source with a corona extending above and below its accretion disk. The only-partial eclipses in its light curve, even at such a high inclination, support this hypothesis. Estimates of the mass of its neutron star lies between 1.14–2.32 solar masses. The optical spectrum of X1822–371 displays strong Hα, Hβ, He I, He II and Bowen Blend features. These features have been extensively studied using the technique of Doppler tomography.
RW Aurigae is a young binary system in the constellation of Auriga about 530 light years away, belonging to the Taurus-Auriga association of the Taurus Molecular Cloud. RW Aurigae B was discovered in 1944.
RY Tauri is a young T Tauri star in the constellation of Taurus about 450 light years away, belonging to the Taurus Molecular Cloud. It is more massive than typical T Tauri stars, and may be an intermediate between this class and the Herbig Ae/Be star type.
AS Leonis Minoris, also known as TYC 2505-672-1, is an eclipsing binary system in the constellation of Leo Minor. It has by far the longest period, 69.1 years, of any known eclipsing binary. During its roughly 3.45 year long eclipses, it fades by 4.5 magnitudes.
HD 104237 is a candidate multiple star system in the southern constellation of Chamaeleon. It has the variable star designation DX Chamaeleontis, abbreviated DX Cha; HD 104237 is the stellar designation from the Henry Draper Catalogue. The system is dimly visible to the naked eye with an apparent visual magnitude that ranges from 6.59 down to 6.70. It is located at a distance of approximately 348 light-years from the Sun based on parallax measurements. The system is positioned just 2′ to the north-east of the 5th magnitude star Epsilon Chamaeleontis, and is a member of the ε Cha association of co-moving stars.
