Gememma's planets, as observed with one of Mesbin's finest observatories. The black dot covering Gememma is a coronagraph/starshield, and is used to block out Gememma's bright photosphere to bring out the otherwise quite dim planets. The bright glow that remains is a diffraction pattern of Gememma's light.

Name: Gememma (Formerly and incorrectly "Rodocer"), Kaywell's Star B.

Designation: Kaywell B

Discovered (Kerbin): Direct imaging by astronomer Kaywell Kerman.

Rediscovered (Mesbin): Naked eye star. Discovered to be nearby by astronomer Gememma Kerman.

Gememma was long thought to be the distant red giant star Rodocer, a well known star visible from the ancestral Kerbol system. Early Mesbin explorers would use it for longitudinal navigation, and get confused why they kept being led off course every few years after a correction to the star map was made. Annoyed by these constant navigation errors, navigator and early astronomer Gememma Kerman decided to measure the position of the star over time. What she found was startling. The star wasn't just moving very quickly through deep space far away from Kaywell. It was moving at exactly the right angular rate to be in orbit around Kaywell at a distance just above that of Reander. She published her results in the scientific journal "Space And Some Things To Find In It" before being lynched by angry astrologers. The star turned out to be a red dwarf star in orbit of Kaywell after all, making Kaywell a double-star system. The star was renamed Gememma's Star (and Rodocer reidentified as a much more distant, dimmer star) and the gang of ravenous astrologers spent the rest of their lives in prison.

Physical Properties

Use of "solar" in this case really means a 1/10th scale, 1/100th mass, 1/100th luminosity ksp-scale Sol, not Kerbol and not the real-scale Sun.

• Radius = 13,800,000 meters. (0.1984 Solar Radii)
• Mass = 2.9823 x 10^27 kilograms. (0.14998 Solar Masses.)
• Luminosity = 0.0021726 Solar Luminosities.
• Habitable Zone Nominal Radius = 0.0466 kau.
• Surface Temperature = 2800 Kelvins.
• Star Color = RGB(255,170,95)
• Rotation Period = 432,000 seconds. (5.0 days.)
• Spectral Type = M8V
• Age = Roughly 5 billion years.
• Main Sequence Lifetime = basically forever. (Several hundred trillion years.)
• Absolute Magnitude (ki = 0.1 ly) = +11.5
• Apparent Magnitude (Mesbin) = -12.5
• Apparent Magnitude (Kerbin, ki = 1e13 m) = -2.2
• Apparent Magnitude (Kerbin, ki = 0.1 ly) = +7.6
• Metallicity [Fe/H] = 0.1 dex.

Orbital Properties

• Parent Body = Kaywell
• Semi Major Axis = 492,000,000,000 meters. (32.88 kau)
• Apoapsis = 599,748,000,000 meters. (40.09 kau)
• Periapsis = 384,252,000,000 meters. (25.69 kau)
• Orbital Period = 1383853697.439 seconds. (43 years, 311 days, 9 hours, 51 minutes, 20 seconds)
• Inclination = 3.22°
• Eccentricity = 0.219
• Argument Of Periapsis = 209°
• Longitude of Ascending Node = 152°
• Mean Anomaly at Epoch = 337°

Gememma orbits in a mildly eccentric orbit around Kaywell. It is "dangerously" close to the gas giant Reander, but simulations over thousands of years have suggested that while Reander's orbit is dynamic, it is not unstable.

Since Gememma seems to be significantly older than the Kaywell system, it is likely that Gememma was captured by Kaywell at some point. There are three possible explanations for capture.

1. Nebular Capture.
2. Ejected Companion.
3. Some combination of the above.

In the Nebular Capture hypothesis, Gememma is captured into the system before the Kaywell system's gas disk had dissipated. This would naturally result in a low eccentricity, low inclination orbit, and it would have likely had a great effect on the formation of the Kaywell system's planets. Gememma's magnetic field would have prevented the accretion of Kaywellian gas onto any of Gememma's planets.

In the Ejected Companion hypothesis, Gememma is captured into the system by ejecting a brown dwarf or stellar companion during a close pass by Kaywell at some point. This may have caused instability in all three stellar systems (Gememma, Kaywell, and the hypothetical companion's system) unless Kaywell's nebula was still present, in which case Kaywell's planets will have either been formed after Gememma was captured or they will have been less unstable due to gas drag.

Planetary System

Gememma has several known planets in orbit around it, several of which exhibit interesting resonances, and two of which are binary planets.

• Ammenon.
• Lowel/Ollym
• Gannovar.
• G1 Gallant.
• Mandrake/Rutherford and moons.
• Pragnik.

Lowel/Ollym is in a 3:1 resonance with Gannovar, which in turn is in a 3:2 resonance with Gallant. They are arranged such that when Gannovar makes its periastron pass, Lowel/Ollym is on the opposite side of Gememma. Pragnik is in a 2:3 resonance with Mandrake/Rutherford, and has a similar arrangement with Mandrake/Rutherford.

The eccentricities of the orbits of Mandrake/Rutherford and Gannovar imply planet-planet scattering had occurred some time in the past, resulting in at least one planet being ejected from the system.

The planetary status of Ammenon and Pragnik are disputed. They may simply be large asteroids, or some kind of dwarf planet.