Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Crux |
Right ascension | 12h 14m 16.9255s [1] |
Declination | −64° 24′ 30.662″ [1] |
Apparent magnitude (V) | 6.18 [2] |
Characteristics | |
Spectral type | B1.5Ia [3] |
U−B color index | −0.73 [2] |
B−V color index | 0.12 [2] |
Variable type | α Cygni [4] |
Astrometry | |
Radial velocity (Rv) | -10.50 [5] km/s |
Proper motion (μ) | RA: -5.62 [1] mas/yr Dec.: 0.15 [1] mas/yr |
Parallax (π) | 0.80 ± 0.30 mas [6] |
Distance | approx. 4,000 ly (approx. 1,300 pc) |
Absolute magnitude (MV) | −6.9 [7] |
Details | |
Mass | 30 [3] M☉ |
Radius | 42 [7] R☉ |
Luminosity | 251,000 [7] L☉ |
Surface gravity (log g) | 2.50 [3] cgs |
Temperature | 20,100 [3] K |
Rotational velocity (v sin i) | 43 [3] km/s |
Other designations | |
Database references | |
SIMBAD | data |
DL Crucis is a variable star in the constellation Crux.
DL Crucis has a visual apparent magnitude of 6.3 so it is just visible with the unaided eye in dark skies. [8] It lies in the small southern constellation of Crux, halfway between η Crucis and ζ Crucis and close to the constellation's brightest star α Crucis. This area of sky lies within the Milky Way and close to the Coalsack Nebula.
DL Crucis has a spectral type of B1.5 Ia, making it a luminous blue supergiant with a temperature over 20,000 K and 251,000 times as luminous as the sun. [7] It has a radius around 42 times, [7] and a mass 30 times that of the Sun. [3]
In 1977 DL Crucis, then referred to as HR 4653, was being used as a comparison star to test the variability of δ Crucis. δ Crucis turned out to be constant relative to several other stars, but the difference in brightness between it and HR 4653 changed by 0.02 magnitude. [10] It was considered likely to be a variable with a period longer than seven hours. [11]
Hipparcos photometry showed that DL Crucis was varying by up to 0.04 magnitude with a main period of 2 days 21 hours It was classified as an α Cygni variable. [12] Shortly afterwards it received its variable star designation of DL Crucis. [13]
A later detailed statistical analysis of the same data found periods of 3.650 and 3.906 days, as well as a first harmonic pulsation, with a maximum brightness range of 0.11 magnitudes. [7]
Lambda Ursae Minoris is a star in the constellation Ursa Minor. It is an M-type red giant with an apparent magnitude of +6.38 and is approximately 880 light years from Earth.
9 Aurigae is a star system in Auriga (constellation). It has an apparent magnitude of about 5, making it visible to the naked eye in many suburban skies. Parallax estimates made by the Hipparcos spacecraft put it at about 86 light-years from the solar system, although individual Gaia Data Release 3 parallaxes place all three components at 88 light years.
CS Camelopardalis is a binary star in reflection nebula VdB 14, in the constellation Camelopardalis.
V533 Carinae is a A-type supergiant and a Alpha Cygni variable star with a mean apparent magnitude of +4.59 in the constellation Carina. It is located at a distance of about 13,000 light years.
V385 Andromedae is a variable star in the constellation Andromeda, about 360 parsecs (1,200 ly) away. It is a red giant over a hundred times larger than the sun. It has an apparent magnitude around 6.4, just about visible to the naked eye in ideal conditions.
NO Aurigae is a pulsating variable star in the constellation Auriga. It is an unusually-luminous asymptotic giant branch star about 3,500 light years away.
V4381 Sagittarii is a variable star in the constellation Sagittarius. A white supergiant of spectral type A2/A3Iab, it is an Alpha Cygni variable that varies between apparent photographic magnitudes 6.57 and 6.62. Its visual apparent magnitude is about 6.54.
V381 Cephei is a triple star system in the northern constellation of Cepheus. Its apparent magnitude is slightly variable between 5.5 and 5.7.
5 Lacertae is a spectroscopic binary in the constellation Lacerta. Its apparent magnitude is 4.36.
V424 Lacertae is a red supergiant variable star in the constellation Lacerta. It is a member of the Lacerta OB1 stellar association.
V1073 Scorpii is a variable star in the constellation Scorpius. It has a non-Greek Bayer designation of k Scorpii. The star has a blue-white hue and is visible to the naked eye with an apparent visual magnitude that fluctuates around +4.87. Parallax measurements yield a distance estimate of approximately 2,920 ly (896 pc) from the Sun, and it is drifting further away with a radial velocity of +7 km/s. It has an absolute magnitude of −6.8
10 Persei is a blue supergiant star in the constellation Perseus. Its apparent magnitude is 6.26 although it is slightly variable.
BH Crucis, also known as Welch's Red Variable, is a star in the constellation Crux. A long period (Mira-type) variable, its apparent magnitude ranges from 6.6 to 9.8 over 530 days. Hence at its brightest it is barely visible with the unaided eye in a rural sky. A red giant, it had been classified ranging between spectral types SC4.5/8-e and SC7/8-e, but appears to have evolved into a C-type spectrum by 2011.
W Crucis is a single-lined eclipsing variable star system in the constellation Crux. It has a spectral class of F8/G1Ia/abe indicating a yellow supergiant with emission lines in its spectrum.
3 Geminorum is a blue supergiant star in the constellation Gemini. It is a small amplitude pulsating variable and a close double star, with a mean combined apparent visual magnitude of about 5.7.
V915 Scorpii is a hypergiant and semiregular variable star, located 1,718 parsecs (5,600 ly) away in the constellation Scorpius. Its apparent magnitude varies between 6.22 and 6.64, being heavily diminshed by 2.93 magnitudes due to interstellar extinction.
HR 4887 is a suspected variable star in the open cluster NGC 4755, which is also known as the Kappa Crucis Cluster or Jewel Box Cluster.
DS Crucis is a variable star near the open cluster NGC 4755, which is also known as the Kappa Crucis Cluster or Jewel Box Cluster. It is in the constellation Crux.
BU Crucis is a variable star in the open cluster NGC 4755, which is also known as the Kappa Crucis Cluster or Jewel Box Cluster.
DU Crucis is a red supergiant and slow irregular variable star in the open cluster NGC 4755, which is also known as the Kappa (κ) Crucis Cluster or Jewel Box Cluster.