Dschubba

STARB0.3IV blue-white subgiant

ILLUSTRATION FROM SPECTRAL TYPE B0.3IV · 28 800 K · 2400 L☉ · VARIABLE, MAG 2.28–2.30 · TIMING NOT TO SCALE

[

OVERVIEW

] STAR

Dschubba is a in the constellation Scorpius, 491.2 from Earth, shining at apparent magnitude 2.29 (). It is catalogued as 7 δ Sco, HD 143275 and HIP 78401, among 5 designations in total.

WHAT IT IS
Blue-white subgiant
HOW FAR
491.2

The light arriving now left it that long ago.

HOW BRIGHT (V)

Bright enough for the naked eye, under a sky dark enough.

WHERE TO LOOK
Scorpius

The patch of sky it sits in, as seen from Earth.

[

THE MODEL

] RADIUS FROM THE LUMINOSITY AND THE TEMPERATURE
DRAG TO ORBIT

CALCULATED · NOT AN OBSERVATION · RADIUS FROM THE LUMINOSITY AND THE TEMPERATURE · SPECTRAL TYPE B0.3IV · 28 800 K · 2400 L☉ · VARIABLE, MAG 2.28–2.30

Drawn from the radius from the luminosity and the temperature 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, at their real positions and drawn from where the camera actually is — so the constellations are wrong, and that is the point. This is the sky from there, not the sky from here.

[

OBSERVING

] FROM WHERE YOU ARE

What it takes to see Dschubba 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.

TONIGHT

Say where you are, and this line says when Dschubba is worth going out for.

[

THROUGH AN EYEPIECE

] 150 MM TELESCOPE · 25 MM EYEPIECE
NE
0′ ACROSS

Bright enough to pick out with your eyes alone, and from a lit street as well as a dark one. Its brightest companion sits 0.10″ away, which at 48× is blended into one star.

48×
1.08
1.25
13.0
0.10 · blended into one star
APPARENT MAGNITUDE ()
2.29 · within reach

A is where the pair was the year it was measured — the ones above, in 2024, and a pair in a real orbit has moved since. The brightest companion is 2.3 magnitudes down on the star itself, which makes it a harder split than the angle alone suggests: the glare of the brighter one is what you are separating it from.

FIND IT ON THE SKY MAP ↗
[

APPARENT PLACE

] EQUINOX J2026.7

Where 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
22.5
PROPER MOTION SINCE
1.01

Computed for 2026-08-27 00:00 UT. Two things separate it from the catalogued position above: Dschubba 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

] GAMMA CASSIOPEIAE ERUPTIVE SHELL STAR
RANGE, AS SAMPLED
2.28 – 2.30

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.

[

DOUBLE STAR

] 1 PAIR
COMPONENTSSEPARATIONPOSITION ANGLEMAGNITUDEMEASURED
0.1″344°4.622024

Separation and position angle are as measured in the year given; a position angle is measured from north, through east. Washington Double Star Catalog 16003-2237.

[

CATALOG DATA

] 13 FIELDS

The 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
Luminosity
2396.62
Variability
Gamma Cassiopeiae eruptive shell star
Variability type ()
GCAS

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)
−8.67
Proper motion (Dec)
−36.9
Radial velocity
−7

OTHER NAMES AND NUMBERS

The identifiers other catalogues file this object under, for anyone joining this data to theirs.

Variable-star designation
Del Sco
Washington Double Star id
16003-2237

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 (1973ARA&A..11...29M, quality B)
[

ALSO KNOWN AS

] 5 DESIGNATIONS
  • Bayer/Flamsteed 7 δ Sco
  • Common name Dschubba
  • HD HD 143275
  • HIP HIP 78401
  • HR HR 5953
[

LOOK IT UP ELSEWHERE

] 3 SERVICES

Each 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.

[

CITE THIS PAGE

] DR1

This 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.

PLAIN TEXT
SpaceCatalog. Dschubba [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/dschubba
BIBTEX
@misc{spacecatalog_dschubba,
  author       = {{SpaceCatalog}},
  title        = {{Dschubba}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/dschubba},
  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.

[

RELATED OBJECTS

] 8 LINKED