Written by OC Wanderer, author of Destiny Among the Stars, a LitRPG sci-fi series set in the real stellar neighborhood. Published October 7, 2026.

Our neighborhood sits inside a bubble that nearby supernovae blew, and the stars that exploded were born in a nursery we can still see. That nursery is Scorpius-Centaurus, or Sco-Cen for short. What is in it?

I wonder what a survey crew would find on arriving there. The stars that helped make the Bubble have exploded, but the nursery keeps a remarkable record of what came before and what is still growing. Sco-Cen is our nearest region of recent massive-star formation, full of small, faint stars and young planets. A crew could visit systems still assembling planets, then follow the trail of a supernova through a star that escaped it. That is quite a survey itinerary.

Sco-Cen is the nearest region of recent massive-star formation, 376 to 466 light-years away

Some of the nursery is already familiar from our night sky: Antares in Scorpius, and Acrux and Beta Crucis in the Southern Cross, belong to this stellar family and can be seen without a telescope.3 Those bright landmarks help me picture a place that otherwise lives in catalogues. Sco-Cen is the closest OB association to the Sun, a loose group of young stars that includes the hot, massive O and B types. It holds at least 150 B stars and one O star across three subgroups named for their parts of the sky: Upper Scorpius, Upper Centaurus-Lupus and Lower Centaurus-Crux.1

Gaia, the European Space Agency's star-mapping satellite, put the subgroups at average distances of 466, 443 and 376 light-years.2 Close enough for astronomers to examine individual stars, far enough to stretch a fictional expedition's ambitions: that is the scale we are dealing with.

In Book 4, Chapter 237, Karen lays out the company's route to the board: "Today it is Sol. Tomorrow it is Alpha Centauri. Then Luhman 16. Then Barnard's Star." Barnard's Star is 5.96 light-years from the Sun. The three Sco-Cen subgroups are 63 to 78 times as far.4 Imagine extending Karen's route that far and finally reaching the nearest nursery of massive stars. Even the word “nearest” asks a lot of a starship.

Destiny crew observing a montage of young stars and disks

Most of what is there is small and faint

The bright giants make it easy to imagine Sco-Cen as a crowd of blazing blue suns. A survey crew's target list would look rather different. A Gaia study found more than 13,000 young objects moving together through this region, and about 19 percent of them are brown dwarfs, objects too light to sustain hydrogen fusion as stars do.5 Set beside the roughly 150 B stars, that puts massive stars at about one member in a hundred, an approximate comparison between different catalogues.6

Most of the survey would be spent among smaller, fainter members. Upper Scorpius follows the familiar Galactic pattern: astronomers counted members from 0.1 to 20 times the Sun's mass and found the same balance of light and heavy stars that field stars show elsewhere, with small stars far outnumbering large ones.7 I like the possibilities that opens up for an expedition. The spectacular stars draw it to the region, but the many quieter systems give it places to explore.

Its three subgroups have different ages, and its planets are caught at different stages

Sco-Cen lets us compare systems growing up at different speeds and ages. The subgroup medians are about 11 million years for Upper Scorpius and 16 and 17 million years for Upper Centaurus-Lupus and Lower Centaurus-Crux, which makes even the oldest more than 250 times younger than the Sun.8 Our own planets have had billions of years to settle into the worlds we know; here we can look for the stages they passed through.

One clue is how much building material remains around the stars. Among K-type stars, a little cooler than the Sun, about 9 percent in Upper Scorpius still hold a full disk of gas and dust, against 4.4 percent in the two older subgroups, roughly half as many.9 Comparing those groups gives us a way to investigate how the planet-making supply changes with age, without waiting millions of years beside one star.

At PDS 70, the planets themselves come into view. This star, about 5 million years old in Upper Centaurus-Lupus, still has a disk with a wide gap, and images show two giant planets, PDS 70 b and c, inside it. Both are still gathering material from the disk around them.10 Imagine a survey crew reaching a system where the giants are still growing. Even its planetary inventory would be a record of work in progress.

TOI-1227 b offers another intriguing stage: a large young planet that may shrink into something much smaller. It circles a very small star in the Musca group within Lower Centaurus-Crux, about 11 million years old. The planet is 0.85 times Jupiter's width, or 9.5 times Earth's, and its discoverers suggest that it is still contracting and will eventually become one of the more common planets smaller than five Earth radii.11 A Jupiter-sized dot on a survey map can hide a very different future.

Its oldest massive stars have already died

Some of the first giants have already exploded: massive stars burn through their fuel quickly, and the older subgroups have given them 15 million years or more. The exciting part is that their surviving neighbours can preserve clues to a vanished star. Sco-Cen's only O star, ζ Ophiuchi, is a runaway moving far faster than its neighbours. Trace its path backward through the Galaxy's gravity alongside PSR B1706−16, a pulsar left by a supernova, and the two meet at one place in Upper Centaurus-Lupus 1.78 million years ago. ζ Ophiuchi is thought to have been its companion, flung out by the blast.12 A speeding star and a spinning remnant give us a way to reconstruct an explosion nobody watched. Our post on stellar death follows what such a star leaves behind.

A model of the Bubble's history, built from the Gaia positions of Sco-Cen's stars, infers 14 supernovae, 13 of them in the two older subgroups, with the cavity around the Sun following from their combined energy.13 That possibility connects the nursery to our own surroundings. A crew setting out from the Sun could be leaving a cavity shaped by the deaths of stars born at its destination.

So what is in the nearest massive-star nursery?

Our survey crew would find mostly small, faint stars, systems with planets still growing, and traces of massive stars that have already died. I would want to follow both ends of that history: the dust becoming new worlds and the runaway stars pointing back to old explosions.

The planets still gathering material make me wonder what that material is made of, and whether a young system could hold more metal than ours. Could the Scorpius-Centaurus region be rich in mineral resources compared to our Solar System?

If you want to follow a crew as their route runs out past the nearest stars, start Destiny Among the Stars.

Endnotes

  1. Thomas Preibisch and Eric Mamajek, “The Nearest OB Association: Scorpius-Centaurus (Sco OB2),” in Handbook of Star Forming Regions, Vol. II (Astronomical Society of the Pacific, 2008), arXiv:0809.0407, which calls Sco-Cen “the nearest region of recent massive star formation” and counts at least about 150 B stars and one O-type star, the runaway ζ Oph. ↩

  2. N. J. Wright and E. E. Mamajek, “The Kinematics of the Scorpius-Centaurus OB Association from Gaia DR1,” Monthly Notices of the Royal Astronomical Society 476 (2018), 381–398, arXiv:1801.08540: Gaia DR1 astrometry for 258 of 433 members; Upper Scorpius 143.0, Upper Centaurus-Lupus 135.9 and Lower Centaurus-Crux 115.2 parsecs (about ±6, ±5 and ±4 parsecs with the DR1 systematic parallax error). Author conversion at 3.2616 light-years per parsec: 466, 443 and 376 light-years. ↩

  3. Preibisch and Mamajek (2008), which lists Antares as a member that has already evolved off the main sequence; Mark J. Pecaut and Eric E. Mamajek, “The Star-Formation History and Accretion-Disk Fraction Among the K-Type Members of the Scorpius-Centaurus OB Association,” MNRAS 461 (2016), 794–815, arXiv:1605.08789, whose member table places β Crucis and α¹ Crucis (Acrux) in Lower Centaurus-Crux. ↩

  4. Canon: Book 4, Chapter 237. Barnard's Star at 5.96 light-years: Barnard's Star (secondary source). Author calculation: 376 ÷ 5.96 = 63 and 466 ÷ 5.96 = 78. ↩

  5. Sebastian Ratzenböck et al., “Significance Mode Analysis (SigMA) for Hierarchical Structures: An Application to the Sco-Cen OB Association,” Astronomy & Astrophysics 677 (2023), A59, DOI: more than 13,000 co-moving young objects, about 19 percent of them substellar, sorted into 37 clusters (Gaia DR3). ↩

  6. Author calculation: about 150 B stars (Preibisch and Mamajek 2008) against more than 13,000 members (Ratzenböck et al. 2023) is about 1.2 percent. The two counts come from different catalogs, so the ratio is approximate. ↩

  7. Preibisch and Mamajek (2008): the empirical mass function of Upper Scorpius, established from 0.1 to 20 solar masses, is consistent with determinations of the field initial mass function. ↩

  8. Mark J. Pecaut, Eric E. Mamajek and Eric J. Bubar, “A Revised Age for Upper Scorpius and the Star Formation History among the F-type Members of the Scorpius-Centaurus OB Association,” The Astrophysical Journal 746 (2012), 154, arXiv:1112.1695: Upper Scorpius 11 ± 1 (statistical) ± 2 (systematic) Myr; Upper Centaurus-Lupus 16 Myr; Lower Centaurus-Crux 17 Myr. Author calculation: 4,600 Myr ÷ 17 Myr is about 270. Ratzenböck et al. 2023b, A&A 678, A71 (arXiv:2302.07853), add that star formation came in four bursts about 5 Myr apart, the largest about 15 Myr ago, and that nine clusters formerly grouped as Upper Scorpius span 3 to 19 Myr. ↩

  9. Pecaut and Mamajek (2016): protoplanetary disk fractions for K-type stars of 9.0 (+4.0, −2.2) percent for Upper Scorpius at about 10 Myr and 4.4 (+1.6, −0.9) percent for Upper Centaurus-Lupus and Lower Centaurus-Crux at about 16 Myr, consistent with a disk e-folding timescale of about 4 to 5 Myr for stars of about one solar mass. ↩

  10. Miriam Keppler et al., “Discovery of a Planetary-Mass Companion within the Gap of the Transition Disk around PDS 70,” A&A 617 (2018), A44, DOI; Sebastiaan Y. Haffert et al., “Two Accreting Protoplanets around the Young Star PDS 70,” Nature Astronomy 3 (2019), 749–754, DOI; NASA Exoplanet Archive, PDS 70 (two confirmed planets; star age about 5.4 Myr). Adrien Žerjal et al., “Chronostar. II. Kinematic Age and Substructure of the Scorpius-Centaurus OB2 Association,” MNRAS 519 (2023), 3992–4009, arXiv:2111.09897, gives 15 ± 3 Myr for the kinematic component that includes PDS 70. ↩

  11. Andrew W. Mann et al., “TESS Hunt for Young and Maturing Exoplanets (THYME). VI. An 11 Myr Giant Planet Transiting a Very-low-mass Star in Lower Centaurus Crux,” The Astronomical Journal 163 (2022), 156, arXiv:2110.09531: radius 0.85 ± 0.05 Jupiter radii (9.5 Earth radii), orbital period 27.4 days, host mass 0.170 ± 0.015 solar masses, group (Musca) age 11 ± 2 Myr, mass upper limit about 0.5 Jupiter masses; NASA Exoplanet Archive, TOI-1227. ↩

  12. R. Neuhäuser et al., “A nearby recent supernova that ejected the runaway star ζ Oph, the pulsar PSR B1706−16, and ⁶⁰Fe found on Earth,” MNRAS 498 (2020), 899–911, DOI: both objects at the same position 1.78 ± 0.21 Myr ago in Upper Centaurus-Lupus, 107 ± 4 parsecs from the Sun, progenitor 16 to 18 solar masses; 107 parsecs is about 349 light-years. Author conversion: 107 × 3.2616 = 349 light-years. The runaway and pulsar are traced through Galactic orbits; the explosion itself was not observed. The only O star in Sco-Cen is ζ Oph (Preibisch and Mamajek 2008). ↩

  13. M. M. Schulreich, J. Feige and D. Breitschwerdt, “Numerical studies on the link between radioisotopic signatures on Earth and the formation of the Local Bubble. II. Advanced modelling of interstellar ²⁶Al, ⁵³Mn, ⁶⁰Fe, and ²⁴⁴Pu influxes as traces of past supernova activity in the solar neighbourhood,” A&A 680 (2023), A39, arXiv:2309.13983: 14 supernovae, 13 in Upper Centaurus-Lupus and Lower Centaurus-Crux and one in V1062 Sco. The model is tied to radioactive iron-60 found in Earth's deep-sea deposits. Zucker et al., Nature 601 (2022), 334–337, DOI, date the start of the Bubble's expansion to about 14 Myr ago. ↩