RR Ind

STARC red star

ILLUSTRATION FROM SPECTRAL TYPE C · 3000 K · 37.3 L☉ · VARIABLE, MAG 8.98–9.41 · PERIOD 140 DAYS · PULSE COMPRESSED

[

OVERVIEW

] STAR

RR Ind is a C red star in the constellation Indus, 1510 from Earth, shining at apparent magnitude 9.25 (). It is catalogued as HD 206652 and HIP 107490.

WHAT IT IS
Red star
HOW FAR
1510

The light arriving now left it that long ago.

HOW BRIGHT (V)

Binoculars reach it; the naked eye does not.

WHERE TO LOOK
Indus

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

[

OBSERVING

] FROM WHERE YOU ARE

What it takes to see RR Ind 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 RR Ind is worth going out for.

[

THROUGH AN EYEPIECE

] 150 MM TELESCOPE · 25 MM EYEPIECE
EYE50MM150MM300MM9.25
TELESCOPE REACHES 13.0

Too faint for your eyes alone. Binoculars reach 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 ()
9.25 · within reach
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
15.1
PROPER MOTION SINCE
0.32

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

] SEMIREGULAR PULSATING GIANT (POORLY DEFINED PERIODICITY)
RANGE, AS SAMPLED
8.98 – 9.41
PERIOD
140 days

For this class the published period is a mean cycle time rather than an ephemeris: the star repeats on that timescale without keeping to it, so counting cycles from a past event would predict a date the star has no obligation to meet.

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, the period and the epoch are the General Catalogue of Variable Stars’s. These elements as data.

[

LIFE OF THIS STAR

] STAGE 3 OF 5

RR Ind is a red giant, past the main sequence and burning helium in a core that has no hydrogen left in it; in about four hundred million years it will shed its outer layers as a planetary nebula and leave a white dwarf behind.

  1. COLLAPSING CLOUD
    took about twenty million years
  2. MAIN SEQUENCE
    lasted about four billion years
  3. GIANT
    about four hundred million years of it
    NOW
  4. PLANETARY NEBULA
    gone in about twenty thousand years
  5. WHITE DWARF
    cooling from then on

NOW With the core out of hydrogen, the star swells enormously and its surface cools to red. It burns helium in the core and hydrogen in a shell around it, and it loses mass from its surface the whole time.

NEXT The outer layers drift away and the exposed core lights them from inside. It is one of the shortest things a star does and one of the most visible — most of the glowing shells in this catalogue are this stage of some star.

EVERY STAGE ON THIS TRACK
COLLAPSING CLOUDtook about twenty million years
A cold clump of gas and dust falls in on itself and heats as it falls. It stops being a cloud and starts being a star at the moment its core is hot enough to fuse hydrogen.
MAIN SEQUENCElasted about four billion years
Hydrogen fuses to helium in the core, and the outward push of that exactly balances the star's own weight. This is the long, steady stretch — nine-tenths of a star's life — and it ends when the core's hydrogen is gone.
GIANTabout four hundred million years of itNOW
With the core out of hydrogen, the star swells enormously and its surface cools to red. It burns helium in the core and hydrogen in a shell around it, and it loses mass from its surface the whole time.
PLANETARY NEBULAgone in about twenty thousand years
The outer layers drift away and the exposed core lights them from inside. It is one of the shortest things a star does and one of the most visible — most of the glowing shells in this catalogue are this stage of some star.
WHITE DWARFcooling from then on
The bare core, about the size of the Earth, held up by nothing but the resistance of its own crushed electrons. No fusion, no fuel, nothing left to do but cool.
  • HOW FIRM No mass has been measured for this star, and past the main sequence its temperature no longer implies one — a red giant of one solar mass and a red supergiant of fifteen are the same colour. The figure above comes from its total output instead, and is unlikely to be better than a factor of two.
  • ALSO Its class is one only an evolved star can have: the carbon on its surface was made in its own interior and dredged up, which is a thing that happens on the asymptotic giant branch and nowhere earlier.

Which stage RR Ind is in was read from its catalogued class, its temperature and its total output at every wavelength — not from its brightness in visible light alone, which understates a cool star by a factor of several. The mass it started with is about half again the Sun's mass, from its luminosity, and that mass is what chooses the track. Every span of time here comes from the standard relation between a star’s mass and how long its fuel lasts, and is rounded to a single figure: they are orders of magnitude and none of them is a date.

[

CATALOG DATA

] 14 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 KIND OF THING IT IS

What the object is in itself, rather than how it happens to look from here.

Spectral type
Luminosity
37.2563
Variability
Semiregular pulsating giant (poorly defined periodicity)
Variability type ()
SRB
Variability period
140
Reference epoch ()

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)
11.65
Proper motion (Dec)
−2.53
Radial velocity
−7.9

OTHER NAMES AND NUMBERS

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

Variable-star designation
RR Ind

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 (1975MSS...C01....0H, quality D)
[

ALSO KNOWN AS

] 3 DESIGNATIONS
  • HD HD 206652
  • HIP HIP 107490
  • Variable star RR Ind
[

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. RR Ind [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-206652
BIBTEX
@misc{spacecatalog_hd-206652,
  author       = {{SpaceCatalog}},
  title        = {{RR Ind}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/hd-206652},
  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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