Kaffaljidhma — Double Star in Cetus
HIP 12706; Gamma Ceti; 86 Ceti
About Kaffaljidhma
Description
Kaffaljidhma, Gamma Ceti, is a wide triple-star system about 80 light-years away. The brightest component is an A2 Vn main-sequence star at magnitude 3.47. The second component, at 2.6 arcseconds separation, is an F3 dwarf at magnitude 6.6. A third distant member rounds out the system. Kaffaljidhma's physical properties make it a typical young A-type dwarf with a close F-type companion.
Observing Tips
Kaffaljidhma is one of the finest double stars in Cetus. A 3-inch telescope at 150x cleanly splits the 2.6-arcsecond pair. The color contrast between the white primary and the warm yellow companion is very pleasing. Kaffaljidhma lies near the head of Cetus, close to the neighboring Pisces boundary. Best observed October through February.
History
The name Kaffaljidhma comes from the Arabic "kaff al-jidhmā'," meaning "the cut-off hand" — a reference to the hand of the Roman goddess Ceres in mythology. The IAU adopted the name in 2016. The double nature was noted by William Herschel in 1780.
Fun Facts
Kaffaljidhma's primary is a young star, only about 800 million years old — one of the younger stars of its spectral type in the nearby galaxy. The system's small angular size allowed rapid orbital motion to be detected: the F-type companion has completed substantial arc of its orbit since Herschel's first measurements.
Observe
1Physical Properties
2Position & Identifiers
3How easy to split?
| Telescope | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| 80 mm refractor 80mm refr. | V. hard+ | V. hard+ | V. hard+ |
| 150 mm Newton 150mm Newt. | Hard+ | Hard+ | Hard+ |
| Celestron C8 (203 mm SCT) C8 203mm | Medium | Medium | Medium |
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
4Visibility
Set a location in User Settings to see visibility data.
5Multiple Star System Triple
Separation over time
Apparent separation over time, computed from ORB6 orbital elements. Steep curves indicate fast-changing pairs — catch them while they're splittable.
Eyepiece View
A: 3.5 · B: 6.2 · Sep: 1.8″ · PA: 299° · N up, E right
Unresolved · Rayleigh: 2.3″ · Dawes: 1.9″ · Eff: 2.3″
Explore
7
Size Comparison
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Compare Stars
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Spectral Classification
10
Hertzsprung-Russell Diagram
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Stellar Lifecycle
12
Blackbody Spectrum
13
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
14
Stellar Fusion
Discover
15Stellar Notes
16
Light Travel Time Machine
17
Relativistic Travel
Nearby in the Sky
Other targets within a few degrees — pan your scope a little and keep exploring.
Visibility scores assume a 150 mm Newton at Bortle 4.
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