SV Peg
ILLUSTRATION FROM SPECTRAL TYPE M7/10 · 2710 K · 14.5 L☉ · VARIABLE, MAG 8.60–9.16 · PERIOD 144.6 DAYS · PULSE COMPRESSED
OVERVIEW
] STARSV Peg is an M7/10 red star in the constellation Pegasus, 762.0 from Earth, shining at apparent magnitude 8.79 (). It is catalogued as HD 209872 and HIP 109070.
- WHAT IT IS
- Red star
- HOW FAR
- 762.0
- HOW BRIGHT (V)
The light arriving now left it that long ago.
Binoculars reach it; the naked eye does not.
OBSERVING
] FROM WHERE YOU AREWhat it takes to see SV Peg 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 SV Peg is worth going out for.
THROUGH AN EYEPIECE
] 150 MM TELESCOPE · 25 MM EYEPIECEToo faint for your eyes alone. Binoculars reach it. Its brightest companion sits 0.50″ away, which at 48× is blended into one star.
- 48×
- 1.08
- 1.25
- 13.0
- 0.50 · blended into one star
- APPARENT MAGNITUDE ()
- 8.79 · within reach
A is where the pair was the year it was measured — the ones above, in 2016, and a pair in a real orbit has moved since.
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
- 16.3
- PROPER MOTION SINCE
- 0.44
Computed for 2026-08-27 00:00 UT. Two things separate it from the catalogued position above: SV Peg 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
- 8.60 – 9.16
- PERIOD
- 144.6 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 and the period are the General Catalogue of Variable Stars’s. These elements as data.
DOUBLE STAR
] 1 PAIR| COMPONENTS | SEPARATION | POSITION ANGLE | MAGNITUDE | MEASURED |
|---|---|---|---|---|
| — | 0.5″ | 4° | 9.3 | 2016 |
Separation and position angle are as measured in the year given; a position angle is measured from north, through east. Washington Double Star Catalog 22057+3521.
CATALOG DATA
] 14 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
- Luminosity
- 14.4944
- Variability
- Semiregular pulsating giant (poorly defined periodicity)
- Variability type ()
- SRB
- Variability period
- 144.6
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)
- 13.94
- Proper motion (Dec)
- −8.76
- Radial velocity
- −1
OTHER NAMES AND NUMBERS
The identifiers other catalogues file this object under, for anyone joining this data to theirs.
- Variable-star designation
- SV Peg
- Washington Double Star id
- 22057+3521
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 (1993yCat.3135....0C, quality E)
ALSO KNOWN AS
] 3 DESIGNATIONS- HD HD 209872
- HIP HIP 109070
- Variable star SV Peg
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 209872
Cross-identifications, measured values and the reference behind each of them.
- ADSobject:"HD 209872"
Papers indexed against this object rather than against the string, newest first.
- VizieR5″ around 331.4253 +35.3485
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. SV Peg [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-209872
@misc{spacecatalog_hd-209872,
author = {{SpaceCatalog}},
title = {{SV Peg}},
howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
year = {2026},
url = {https://spacecatalog.org/object/hd-209872},
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.