DT Cru
ILLUSTRATION FROM MEASURED TEMPERATURE · 21 200 K · 5.04 L☉ · VARIABLE, MAG 9.91–10.13 · TIMING NOT TO SCALE
OVERVIEW
] STARDT Cru is a B3 blue-white star in the constellation Crux, 791.6 from Earth, shining at apparent magnitude 10.02 (). It is catalogued as HD 312137 and HIP 62919.
- WHAT IT IS
- Blue-white star
- HOW FAR
- 791.6
- HOW BRIGHT (V)
The light arriving now left it that long ago.
A small telescope reaches it.
THE MODEL
] CATALOGUED RADIUSCALCULATED · NOT AN OBSERVATION · CATALOGUED RADIUS · MEASURED TEMPERATURE · 21 200 K · 5.04 L☉ · VARIABLE, MAG 9.91–10.13
Drawn from the catalogued radius and from the same properties the picture at the top of this page uses, at the distance a flight to it would stop. Drag it, or use the arrow keys, to look from another direction. The stars behind are the 498,631 this catalogue holds real distances for, drawn from where the camera actually is — but every one of them is within 170 parsecs of the Sun and this object is much further out, so what is in the frame is that whole neighbourhood seen from outside it, piled into a knot around the Sun. The rest of the sky from here is not something this catalogue knows.
OBSERVING
] FROM WHERE YOU AREWhat it takes to see DT Cru for yourself. Everything in this part of the page is worked out for a real horizon, a real night and the equipment you say you have.
Say where you are, and this line says when DT Cru is worth going out for.
THROUGH AN EYEPIECE
] 150 MM TELESCOPE · 25 MM EYEPIECEOut of reach of binoculars; a 150 mm telescope reaches it. It will be a point of light in anything: a star is far enough away that no aperture on Earth gives it a width, and all the equipment changes is how easily you find it.
- 48×
- 1.08
- 1.25
- 13.0
- APPARENT MAGNITUDE ()
- 10.02 · within reach
APPARENT PLACE
] EQUINOX J2026.7Where a telescope has to be pointed today, which is not quite where the catalogue records the object: the coordinate grid itself has turned since the year 2000 the catalogue is referred to.
- RIGHT ASCENSION
- DECLINATION
- GRID TURNED SINCE
- 14.6
- PROPER MOTION SINCE
- 0.11
Computed for 2026-08-27 00:00 UT. Two things separate it from the catalogued position above: DT Cru has moved under its own proper motion, and the coordinate grid has turned under it — about fifty arcseconds a year of precession since 2000, and the small nodding of the Earth’s axis on top of that. Aberration and refraction are not included, and neither is parallax; each is under an arcminute, which is also about as well as the catalogued position is known. The same figure for any date.
VARIABILITY
] SLOWLY PULSATING B STAR- RANGE, AS SAMPLED
- 9.91 – 10.13
No period is published for this star, so there is no cycle to count. The catalogue records that it varies and by how much, and not how often.
The range is the spread the Hipparcos satellite measured, converted to the visual scale. It is approximate: the satellite sampled the star on a schedule of its own, and where a star spends little of its cycle at an extreme — the floor of an eclipse, most obviously — the sampling can miss it altogether. The classification is the General Catalogue of Variable Stars’s. These elements as data.
CATALOG DATA
] 16 FIELDSThe raw catalogue values, as the source published them, with the error bars where one was published — sorted by what each set of figures is about rather than by the order they happened to be stored in.
WHAT IT IS MADE OF
What the object is in itself, rather than how it happens to look from here.
- Spectral type
- Surface temperature
- 21 248
- Luminosity
- 5.03965
- Radius
- 7.398
- Surface gravity (log g)
- Variability
- Slowly pulsating B star
- Variability type ()
- LPB:
HOW BRIGHT IT IS
What the light adds up to, measured through one filter at a time. A magnitude is a brightness on a backwards scale — the smaller the number, the brighter the object.
- Colour index (B−V)
- Variable magnitude, brightest
- Variable magnitude, faintest
WHERE IT IS AND HOW IT MOVES
Position, motion across the sky and the size it covers on it. These are measurements of the object as seen from here, so every one of them depends on where here is.
- Proper motion (RA)
- −4
- Proper motion (Dec)
- −1.28
- Radial velocity
- 0
OTHER NAMES AND NUMBERS
The identifiers other catalogues file this object under, for anyone joining this data to theirs.
- Variable-star designation
- DT Cru
WHERE THESE FIGURES CAME FROM
Which catalogue, paper or model each of the fields above was read from, where the source named one.
- Spectral type from
- SIMBAD (1949AnHar.112....1C, quality E)
- Stellar parameters from
- Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: above 7,500 GSP-Phot's temperature and extinction are degenerate
ALSO KNOWN AS
] 3 DESIGNATIONS- HD HD 312137
- HIP HIP 62919
- Variable star DT Cru
LOOK IT UP ELSEWHERE
] 3 SERVICESEach link carries the identifier printed beside it. Nothing on this page is a measurement of our own, so a number that disagrees with one of these is worth reporting — and a service that has never catalogued this object under this name will say so plainly.
- SIMBADHD 312137
Cross-identifications, measured values and the reference behind each of them.
- ADSobject:"HD 312137"
Papers indexed against this object rather than against the string, newest first.
- VizieR5″ around 193.4223 -61.2159
Every published table with a row at this position, searched by coordinates rather than by name.
CITE THIS PAGE
] DR1This page is live and its numbers move when an upstream refreshes, so the citation names the release the rows belong to rather than the day you read them. The release itself is frozen, republished as a bundle, and is what a data-availability statement should point at.
SpaceCatalog. DT Cru [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-312137
@misc{spacecatalog_hd-312137,
author = {{SpaceCatalog}},
title = {{DT Cru}},
howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
year = {2026},
url = {https://spacecatalog.org/object/hd-312137},
note = {Catalogue entry, data release DR1 (2026-08-21). Values from HYG Database v4.1.}
}The values above were taken from HYG Database v4.1 — CC-BY-SA-4.0. Citing this page does not replace citing that catalogue, and its licence is share-alike: the terms reach whatever you build from these rows.