CEA 7 Leg 5

Niamh Kaminari

Leg 5 is the penultimate leg of the Celebration of Early Astronomy 7, ending at the first ever discovered black hole, Cygnus X-1! This is a two week leg with a mid-week event.

One of the additional waypoints is KOI 1701, put in for the challenge of landing on the 45G planet. Use Extreme Caution if you attempt this, and it is highly recommended to turn in exploration data prior to attempting.

Dates

Start Date: February 23, 2025
End Date: March 09, 2025

Distances

Basecamp Line: 2,590.68 Ly
Main Waypoints: 4,635.11 Ly
Optional Waypoints: 7,686.35 Ly

Map, (click for full size):

Basecamp: V1357 Cygni
Mid-Leg Event: HR 7678

Main Waypoints

  • Map References quick reference list, more details below
    • IC 4996 DAM 9
    • V1820 Cygni
    • HR 7678
    • CSI+29-19529
    • HD 191612
    • V1357 Cygni

Main Waypoints Details

  • Map Reference: IC 4996 DAM 9
    • POI: IC 4996
    • IC 4996 is a small cluster in the Cygnus constellation about 5,600 Ly from our solar system. It is also very young at only 9 million years old. Because of that theyre are some stars in it that haven’t yet reached their main sequence stage. As a result this cluster is studied to research pre-main sequence stage of stellar evolution.
    • SIMBAD Link
    • EDSM Link
  • Map Reference: V1820 Cygni
    • POI: NGC 6871
    • NGC 6871 is a small young cluster in the Cygnus constellation, located roughly 5,135 Ly from our solar system. It has fewer than 50 members. Most of the members are blue and white stars. The cluster was discovered by Wilhelm von Struve in 1825.
    • SIMBAD Link
    • EDSM Link
  • Map Reference: HR 7678
    • POI: V1768 Cygni
    • HR 7678, also known as V1768 Cygni, is a blue supergiant star in the Cygnus constellation, located roughly 8,000 Ly from our solar system.
    • SIMBAD Link
    • EDSM Link
  • Map Reference: CSI+29-19529
    • POI: NGC 6842
    • NGC 6842 is a planetary nebula on the border of the Cygnus and Vulpeculae constellations, it was discovered in 1919 by Heber Doust Curtis.
    • SIMBAD Link
    • EDSM Link
  • Map Reference: HD 191612
    • POI: Cygnus OB 3 Association
    • HD 191612 is a binary star system in the Cygnus constellation. It is located roughtly 6,100 Ly from our solar system and is part of the Cygnus OB 3 association. In 1972 astronomer N. R. Walborn proposed this star as a Of?p type stellar classification. Later in 1989 the Einstein Observatory listed it as a possible X-Ray Binary due to having high x-ray luminosity. Then in 1992 another study of OB stars found that the spectrum for HD 191612 was different than the one reported by Walborn in 1972, which led to a 2003 study that showed that HD 191612 alternated between two spectral states. It was shown to have a cycle time of roughly 540 days, which seemed too long to be explained by normal rotation of pulsation. In 2006 a strong magnetic -1.5 kilogauss field was discovered, making it the second ever O-type star found to have a strong magnetic field, the other being Theta-1 Orionis C.

      By 2007, the combination of earlier observations along with lack of radial velocity suggested a binary system with an orbital period of 1,542 days (+/- 14) with a B-type main sequence companion star with about half the mass of the primary star. In 2011 the magnetic field was confirmed and found to also vary with a period of 537 days, matching the spectral variation, supporting that the star was an oblique rotator, with the magnetic field oriented at a different angle than the stellar poles by 30 degrees tilt.

      For in-game peculiarity this is also the only known system with an F-class supergiant in a planetary orbit around another star.
    • SIMBAD Link
    • EDSM Link
  • Map Reference: V1357 Cygni
    • POI: Cygnus X-1
    • Cygnus X-1 is a microquasar, and was the first x-ray source widely accepted to be a black hole. First discovered in 1964, it is one of the strongest X-ray sources detectable from Earth. Estimated mass is roughly 21x that of our sun, but has shown to be too small to be any other known type of star or object besides a black hole. The event horizon radius is estimated to be 300km in size. — It orbits in a binary system with blue supergiant HDE 226868 at 0.2AU.

      Cygnus X-1 is thought to be orbited by a thin, flat disk of accreting matter known as an accretion disk. While not represented in-game, these are highly heated disks of matter from the friction cuased by vast differences in orbital speeds as the proximity to the black hole increaes, with the innermost orbits forming a plasma. Accretion disks emit massive amounts of x-rays, which begin as lower energy photons in the accretion disk and are given more energy through the process of Compton scattering from extremely high temperature electrons from the corona surrounding the accretion disk.

      As the matter from the accretion disk dalls towards the black hole, it loses massive amounts of gravitational potential energy. Due to law of conservation of energy, that energy has to go somewhere, which it does in the form of jets of matter flowing outwards from the black hole accelerated to relativistic velocities.

      In 2006, Cygnus X-1 became the first stellar-mass black hole found to display evidence of gamma-ray emission in the very high energy band above 100 GeV.

      Cygnus X-1’s companion star is HDE 226868, an O-type supergiant with a surface temperature of 31,000 Kelvin, and a mass roughtly 20-40 times that of our Sun. The surface of HDE 226868 is tidally distorted by the gravity of the black hole, causing it to be tear drop shaped, and causes the optical birghtness of the star to vary by 0.06 magnitude during each 5.6 day orbit.

      Cygnus X-1 is the subject of a two-part song by the band Rush.

      Additionally the 1979 Disney movie The Black Hole features a black hole called “The Cygnus” in the movie, which presumably would be Cygnus X-1.
    • SIMBAD Link
    • EDSM Link

Additional Waypoints

  • Map References quick reference list, more details below
    • KOI 1701
    • IC 4996 DAM 9
    • V1820 Cygni
    • HR 7678
    • CSI+29-19529
    • Blaa Eohn YZ-G d10-0
    • HD 191612
    • V1357 Cygni

Additional Waypoints Details

  • Map Reference: KOI 1701
    • POI: Via Gravitatis (Extreme Caution!)
    • KOI-1701.01 is an unconfirmed exoplanet around the star KOI-1701. It is thought to be a gas giant, however the game generated it as a landable metal-rich body, resulting in the wackiness of a 45.32 G landable body.
    • SIMBAD Link
    • EDSM Link
  • Map Reference: Blaa Eohn YZ-G d10-0
    • POI: Planet of Slightly Lesser Death
    • Like the infamous Monde de la Morte (Spoihaae XE-X D2-9), this system consists of a planet which orbits perpendicular to the core white dwarf’s jet cones close enough to pass through them at either end. While not passing as near as the exclusion zone unlike its eponym, the cones themselves still create a severe hazard for landing which should not be attempted while the planet is inside the jets themselves.
    • EDSM Link