HAT-P-39
ILLUSTRATION FROM MEASURED TEMPERATURE · 6430 K
OVERVIEW
] STARHAT-P-39 is a star in the constellation Gemini, 2273 from Earth, shining at apparent magnitude 12.28 ().
- WHAT IT IS
- Star
- HOW FAR
- 2273
- HOW BRIGHT (V)
The light arriving now left it that long ago.
A small telescope reaches it.
THE MODEL
] CATALOGUED RADIUSCALCULATED · NOT AN OBSERVATION · CATALOGUED RADIUS · MEASURED TEMPERATURE · 6430 K
Drawn from the catalogued radius 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, drawn from where the camera actually is — but every one of them is within 170 parsecs of the Sun and this object is much further out, so what is in the frame is that whole neighbourhood seen from outside it, piled into a knot around the Sun. The rest of the sky from here is not something this catalogue knows.
OBSERVING
] FROM WHERE YOU AREWhat it takes to see HAT-P-39 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 HAT-P-39 is worth going out for.
THROUGH AN EYEPIECE
] 150 MM TELESCOPE · 25 MM EYEPIECEOut of reach of binoculars; a 150 mm telescope reaches it. Its brightest companion sits 11.2″ away, which at 48× is cleanly split.
- 48×
- 1.08
- 1.25
- 13.0
- · AC
- 11.2 · cleanly split
- APPARENT MAGNITUDE ()
- 12.28 · 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. The brightest companion — AC — is 7.5 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.
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
- 22.4
- PROPER MOTION SINCE
- none published
Computed for 2026-08-27 00:00 UT. No proper motion is published for HAT-P-39, 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. 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| COMPONENTS | SEPARATION | POSITION ANGLE | MAGNITUDE | MEASURED |
|---|---|---|---|---|
| AC | 11.2″ | 304° | 19.8 | 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 07350+1750.
CATALOG DATA
] 7 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.
- Surface temperature
- 6430
- Radius
- 1.625
- Mass
- 1.404
THE ORBIT
The shape of the path, where the object sits on it, and the instant those figures were true of. An orbit is a fit to observations and drifts away from the real one either side of its epoch.
- Stars in system
- 2
- Planets in system
- 1
OTHER NAMES AND NUMBERS
The identifiers other catalogues file this object under, for anyone joining this data to theirs.
- Washington Double Star id
- 07350+1750
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
- NASA Exoplanet Archive composite parameters
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.
- SIMBADHAT-P-39
Cross-identifications, measured values and the reference behind each of them.
- ADSobject:"HAT-P-39"
Papers indexed against this object rather than against the string, newest first.
- VizieR5″ around 113.7583 +17.8300
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. HAT-P-39 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hat-p-39
@misc{spacecatalog_hat-p-39,
author = {{SpaceCatalog}},
title = {{HAT-P-39}},
howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
year = {2026},
url = {https://spacecatalog.org/object/hat-p-39},
note = {Catalogue entry, data release DR1 (2026-08-21). Values from NASA Exoplanet Archive (Planetary Systems Composite Parameters).}
}The values above were taken from NASA Exoplanet Archive (Planetary Systems Composite Parameters) — Public domain (NASA). Citing this page does not replace citing that catalogue.