Circumstellar disks observed around five massive Herbig Be stars

Star system: VOS 70 | Distance from the Sun: 3810 light years

Herbig Be stars are young, massive stars that are still in the early stages of their development. Understanding whether these stars host disks of dust and gas is essential to determine if they can form giant planets. A recent survey of 24 of these massive young stellar objects, located within 3,000 light-years of Earth, has provided new insights into the existence and nature of these planet-forming environments.

The research identified 1.3-millimeter radio emission from 5 out of 24 surveyed Herbig Be stars, which have masses ranging between 4.3 and 12.9 times that of our Sun. These detections suggest the presence of circumstellar disks—flattened, rotating clouds of gas and dust that orbit a young star.

The team used the Submillimeter Array, a collection of radio antennas, to observe these systems. Follow-up observations at 0.87 millimeters confirmed the presence of dust that is partially opaque to certain types of light, supporting the conclusion that these disks are reservoirs for potential planet formation.

The findings show that the detected disks follow scaling relationships established for lower-mass stars, indicating that the potential for giant planet formation persists even in more massive stellar systems. While many of the stars in the survey did not show detectable disks, this is likely due to the sensitivity limits of the equipment, the process of photoevaporation where starlight clears away disk material, or the physical influence of nearby companion stars.

Key findings
- Circumstellar disks were identified around 5 massive Herbig Be stars.
- Observed disk masses are sufficient to support the formation of giant planets.
- Disk properties align with established patterns found in lower-mass young stellar objects.
- No evidence was found that intense radiation from massive stars rapidly destroys these disks.
- High non-detection rates are attributed to survey limits, photoevaporation, and companion star dynamics.

Scientific study

A λ=1.3 millimeter Survey for Disks around Herbig Be Stars (external link)