γ Cyg
ILLUSTRATION FROM MEASURED TEMPERATURE · 5790 K
OBSERVING
] FROM WHERE YOU AREWhat it takes to see γ Cyg 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 γ Cyg is worth going out for.
THROUGH AN EYEPIECE
] 150 MM TELESCOPE · 25 MM EYEPIECEBright enough to pick out with your eyes alone, and from a lit street as well as a dark one. 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 ()
- 2.23 · within reach
APPARENT PLACE
] EQUINOX J2026.8Where 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
- 12.2
- PROPER MOTION SINCE
- none published
Computed for 2026-10-11 00:00 UT. No proper motion is published for γ Cyg, so nothing here moves the object; what separates this from the catalogued position above is the coordinate grid turning under it — about fifty arcseconds a year of precession since 2000, and the small nodding of the Earth’s axis on top of that. The catalogue it came from publishes no error for that position, so nothing here says how far this arithmetic can be trusted — the digits above are as precise as the place they were computed from, and no more. Aberration, parallax and refraction are left out. Aberration swings every position by up to twenty arcseconds over a year; parallax stays under an arcsecond for all but the nearest stars; refraction is nothing overhead and about half a degree at the horizon, where it answers to the air, not the sky. The same figure for any date.
LIFE OF THIS STAR
] STAGE 2 OF 5γ Cyg is a yellow star on the main sequence, fusing hydrogen in its core — about ten billion years of it in all — and when that hydrogen is gone it will swell into a red giant, and end as a white dwarf.
- COLLAPSING CLOUDtook about fifty million years
- MAIN SEQUENCEabout ten billion years in allNOW
- RED GIANTabout a billion years of it, when it comes
- PLANETARY NEBULAgone in about twenty thousand years
- WHITE DWARFcooling from then on
NOW 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.
NEXT 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.
EVERY STAGE ON THIS TRACK
- COLLAPSING CLOUDtook about fifty 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 SEQUENCEabout ten billion years in allNOW
- 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.
- RED GIANTabout a billion years of it, when it comes
- 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 luminosity class is recorded for this star — the catalogue gives its temperature class and stops there — so which stage it is in was read from how far its brightness sits above where a star of its temperature would sit on the main sequence. That is a best estimate rather than a classification.
- ALSO No mass has been measured for this star. The figure above is inferred from its temperature by way of the main-sequence relation between the two, which is tight enough to be worth stating and is still an inference.
Which stage γ Cyg 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 the Sun's own mass, from its temperature, 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, rounded to a single figure. They are orders of magnitude and none of them is a date.
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 KIND OF THING IT IS
What the object is in itself, rather than how it happens to look from here.
- Surface temperature
- 5793
- Surface gravity (log g)
- Metallicity ([Fe/H])
- ±0.23
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.
- Apparent magnitude ()
- Apparent magnitude ()
- Apparent magnitude ()
- Apparent magnitude ( band)
- Apparent magnitude ()
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.
- −6
- Redshift (z)
WHEN IT WAS FOUND
Who first saw it, from where, and by what method.
- Discovered by
- Edward Emerson Barnard
OTHER NAMES AND NUMBERS
The identifiers other catalogues file this object under, for anyone joining this data to theirs.
- OpenNGC type code
- *
- Wikidata item
- Q932017
- Wikipedia article
- IC 1318
WHERE THESE FIGURES CAME FROM
Which catalogue, paper or model each of the fields above was read from, where the source named one.
- Stellar parameters from
- Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)
- Metallicity from
- Median of 6 spectroscopic determinations in 7 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them
ALSO KNOWN AS
] 5 DESIGNATIONS- BD BD +39 4159
- Common name gam Cyg
- HD HD 194093
- HIP HIP 100453
- IC IC 1318
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.
- SIMBADIC 1318
Cross-identifications, measured values and the reference behind each of them.
- ADSobject:"IC 1318"
Papers indexed against this object rather than against the string, newest first.
- VizieR5″ around 305.5570 +40.2567
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. γ Cyg [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/ic-1318
@misc{spacecatalog_ic-1318,
author = {{SpaceCatalog}},
title = {{γ Cyg}},
howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
year = {2026},
url = {https://spacecatalog.org/object/ic-1318},
note = {Catalogue entry, data release DR1 (2026-08-21). Values from OpenNGC.}
}The values above were taken from OpenNGC — 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.
That catalogue asks for this acknowledgement: OpenNGC, Mattia Verga (github.com/mattiaverga/OpenNGC). Fields derived from it stay under CC BY-SA 4.0.