HD 155408

STARG5III yellow giant

ILLUSTRATION FROM SPECTRAL TYPE G5III · 5560 K · LUMINOSITY CLASS

[

OVERVIEW

] STAR

HD 155408 is a in the constellation Ara, shining at apparent magnitude 7.90 (). It is catalogued as HIP 84278.

WHAT IT IS
Yellow giant
HOW BRIGHT (V)

Binoculars reach it; the naked eye does not.

WHERE TO LOOK
Ara

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

[

OBSERVING

] FROM WHERE YOU ARE

What it takes to see HD 155408 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 HD 155408 is worth going out for.

[

THROUGH AN EYEPIECE

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

Too faint for your eyes alone. Binoculars reach it. Its brightest companion sits 2.50″ away, which at 48× is split, with the two all but touching.

48×
1.08
1.25
13.0
2.50 · split, with the two all but touching
APPARENT MAGNITUDE ()
7.90 · within reach

A is where the pair was the year it was measured — the ones above, in 2015, and a pair in a real orbit has moved since. The brightest companion is 4.6 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
20.4
PROPER MOTION SINCE
0.17

Computed for 2026-08-27 00:00 UT. Two things separate it from the catalogued position above: HD 155408 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.

[

DOUBLE STAR

] 1 PAIR
COMPONENTSSEPARATIONPOSITION ANGLEMAGNITUDEMEASURED
2.5″54°12.52015

Separation and position angle are as measured in the year given; a position angle is measured from north, through east. Washington Double Star Catalog 17137-4757.

[

CATALOG DATA

] 7 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

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)

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)
−2.89
Proper motion (Dec)
−5.84
Radial velocity
0

OTHER NAMES AND NUMBERS

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

Washington Double Star id
17137-4757

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 (1978MSS...C02....0H, quality C)
[

ALSO KNOWN AS

] 2 DESIGNATIONS
  • HD HD 155408
  • HIP HIP 84278
[

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. HD 155408 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-155408
BIBTEX
@misc{spacecatalog_hd-155408,
  author       = {{SpaceCatalog}},
  title        = {{HD 155408}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/hd-155408},
  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.

[

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