CFHTWIR-Oph 98 A
ILLUSTRATION FROM MEASURED TEMPERATURE · 2320 K
OBSERVING
FROM WHERE YOU AREWhat it takes to see CFHTWIR-Oph 98 A 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 CFHTWIR-Oph 98 A is worth going out for.
THROUGH AN EYEPIECE
150 MM TELESCOPE · 25 MM EYEPIECEIts brightest companion sits 1.50″ away, which at 48× is right at the limit — a steady night and a good eye.
- 48×
- 1.08
- 1.25
- 13.0
- 1.50 · right at the limit — a steady night and a good eye
A is where the pair was the year it was measured — the ones above, in 2020, and a pair in a real orbit has moved since.
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
- 22.6
- PROPER MOTION SINCE
- none published
Computed for 2026-11-06 00:00 UT. No proper motion is published for CFHTWIR-Oph 98 A, 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.
DOUBLE STAR
1 PAIR| COMPONENTS | SEPARATION | POSITION ANGLE | MAGNITUDE | MEASURED |
|---|---|---|---|---|
| — | 1.5″ | 319° | 16.4 | 2020 |
Separation and position angle are as measured in the year given; a position angle is measured from north, through east. Washington Double Star Catalog 16277-2359.
SPECTRUM
A SPECTRUM OF ITS TYPENo survey in this catalogue has measured CFHTWIR-Oph 98 A’s own spectrum: the one that reaches deepest saturates on the brightest stars, and no spectrograph has been pointed at the whole sky. What is drawn below is the average of several real stars of the same class, M6 V — the nearest class the atlas holds to M9-L1. It shows what a star like this one shows, and every line named on it is a line of the type rather than a measurement of CFHTWIR-Oph 98 A.
A star gives out light at every wavelength at once. The dark gaps are atoms in the thin gas above its surface, each one removing the single colour it is able to absorb — which is how a list of ingredients is read off something nobody will ever touch.
Point at a labelled line — or an element above — to see which atom makes it and where it falls.
Pickles (1998) stellar spectral flux library. M6 V — the average of several real stars of this type, not an observation of any one star. Sampled every 5 angstroms; 1,895 points rebinned onto 1,024 log-spaced display points and normalised to the median flux. Brightness is scaled to this spectrum’s own middle value, so the shape is the measurement and the height is not. The 2 lines named above are the ones that stand clear of the scatter and of the features around them; a spectrum at this sampling holds many more that it cannot separate. The samples themselves, as JSON, CSV or VOTable.
LIFE OF THIS STAR
STAGE 2 OF 3CFHTWIR-Oph 98 A is a subgiant: it has used up the hydrogen in its core, it has begun to swell and cool, and it is on its way off the main sequence. In about forty trillion years it will swell into a supergiant, and end by exploding as a supernova and leaving a neutron star.
- COLLAPSING CLOUDtook about five hundred million years
- MAIN SEQUENCEat the end of itNOW
- WHITE DWARFlong after the universe as it is now
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. This star is at the very end of that: its spectrum is classed as a subgiant, which is what a star is called in the short crossing between running out of core hydrogen and swelling into a giant.
NEXT 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.
EVERY STAGE ON THIS TRACK
- COLLAPSING CLOUDtook about five hundred 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 SEQUENCEat the end of itNOW
- 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.
- WHITE DWARFlong after the universe as it is now
- 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 A subgiant is the hardest kind of star to place. It is between two stages rather than in one of them, it is the shortest stretch of a star's life, and the mass it started with is what decides how long the crossing takes — so the timing above is the least firm figure in this section.
Which stage CFHTWIR-Oph 98 A 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 a tenth of the Sun's mass, from a published model fit, 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
8 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.
- Spectral type
- Surface temperature
- 2320
- Radius
- 0.245
- Mass
- 0.0147
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
- 1
- 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
- 16277-2359
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
1 SERVICEEach 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.
- VizieR5″ around 246.9343 -23.9811
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. CFHTWIR-Oph 98 A [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/cfhtwir-oph-98-a
@misc{spacecatalog_cfhtwir-oph-98-a,
author = {{SpaceCatalog}},
title = {{CFHTWIR-Oph 98 A}},
howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
year = {2026},
url = {https://spacecatalog.org/object/cfhtwir-oph-98-a},
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) — No licence stated; acknowledgement requested. Citing this page does not replace citing that catalogue.
That catalogue asks for this acknowledgement: This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Cite Christiansen et al. (2025), Planetary Science Journal (doi:10.3847/PSJ/ade3c2), and the literature reference given with each value.