I Early Catalog of Planet-Hosting Multiple Star (≥ 3) Systems

  • I
  • Thread starter Thread starter Astronuc
  • Start date Start date
  • Tags Tags
    Exoplanets
AI Thread Summary
The discussion centers on a catalog of triple and higher-order star systems that host exoplanets, revealing about 30 triple and a few quadruple systems identified as of July 2022. These systems are hierarchically structured, with most stars being main-sequence types, primarily A, F, and G, while tertiary components are typically low-mass M stars. The catalog highlights that nearly 40 planets have been discovered, predominantly gas giants and terrestrial types, using methods like Radial Velocity and Transit. A notable point is the underreported fact that the Sun is among the top 5% of main-sequence stars by mass, contrasting with common perceptions of "average" stars. The findings suggest a need for further exploration and expansion of the database as future planetary search missions progress.
Astronuc
Staff Emeritus
Science Advisor
Gold Member
Messages
22,340
Reaction score
7,138
Interesting paper of triple and higher order star systems with planets.

An Early Catalog of Planet Hosting Multiple Star Systems of Order Three and Higher​

https://arxiv.org/abs/2209.11346

ABSTRACT - We present a catalog (status July 1, 2022) of triple and higher order systemsidentified containing exoplanets based on data from the literature, including various analyses. We explore statistical properties of the systems with focuson both the stars and the planets. So far, about 30 triple systems and one to three quadruple systems, including (mildly) controversial cases, have been found. The total number of planets is close to 40. All planet-hosting triple star systems are highly hierarchic, consisting of a quasi-binary complemented by a distant stellar component, which is in orbit about the common center of mass. Furthermore, the quadruple systems are in fact pairs of close binaries ("double-doubles"), with one binary harboring a planet. For the different types of star-planet systems, we introduce a template for the classifications of planetary orbital configurations in correspondence to the hierarchy of the system and the planetary host. The data show that almost all stars are main-sequence stars, as expected. However, the stellar primaries tend to be more massive (i.e., corresponding to spectral types A, F, and G) than expected from single star statistics, a finding also valid for stellar secondaries but less pronounced. Tertiary stellar components are almost exclusively low-mass stars of spectral type M. Almost all planets have been discovered based oneither the Radial Velocity or the Transit method. Both gas giants (the dominant type) and terrestrial planets (including super-Earths) have been identified. We anticipate the expansion of this data base in the light of future planetary search missions.

https://phys.org/news/2023-05-astrophysicists-planet-hosting-three-star.html

Interesting comment:
The data show that almost all stars are main-sequence stars, as expected. However, the stellar primaries tend to be more massive (i.e., corresponding to spectral types A, F, and G) than expected from single star statistics, a finding also valid for stellar secondaries but less pronounced. Tertiary stellar components are almost exclusively low-mass stars of spectral type M.
"
 
  • Like
  • Informative
Likes pinball1970, Drakkith and DennisN
Astronomy news on Phys.org
There is a point made with numbers, though these vary. Namely that Sun is a high mass star - it is pointed out that this is rarely stated.
The two statistics they quote are somewhat divergent and not specific to Sun, but Sun is in about top 5% of main sequence stars.
 
  • Wow
Likes pinball1970
snorkack said:
There is a point made with numbers, though these vary. Namely that Sun is a high mass star - it is pointed out that this is rarely stated.
The two statistics they quote are somewhat divergent and not specific to Sun, but Sun is in about top 5% of main sequence stars.
Certainly never reported like that in the media or pop sci.

"Average star" Top 5% is not average.

EDIT: from wiki "Sun has an absolute magnitude of +4.83, estimated to be brighter than about 85% of the stars in the Milky Way, most of which are red dwarfs.[30][31] "
 
Last edited:
pinball1970 said:
Certainly never reported like that in the media or pop sci.

"Average star" Top 5% is not average.

EDIT: from wiki "Sun has an absolute magnitude of +4.83, estimated to be brighter than about 85% of the stars in the Milky Way, most of which are red dwarfs.[30][31] "
For something that can be analyzed, see
https://en.wikipedia.org/wiki/List_of_nearest_stars_and_brown_dwarfs
which at present covers 20 ly, and does have the disadvantage of being editable (and being Wikipedia)
Grouping by spectral class, I count:
  1. 2 A stars: Sirius A and Altair
  2. 1 F star: Procyon A
  3. 7 G stars. This takes more detailed breakdown... By brightness, α Centauri A, Achird A, and δ Pavonis are brighter than Sun. By mass, Achird A is less massive although brighter. In total, there are thus 6 main sequence stars brighter than Sun, and 5 that are more massive. We are at a total on 10 A, F and G stars combined
  4. 15 K stars
  5. 79 M stars (including the M8 ones)
  6. 2 L brown dwarfs
  7. 16 T brown dwarfs
  8. 4 Y brown dwarfs. Probably not complete (maybe T is not complete either), and not all Y objects qualify as stars.
  9. 6 white dwarfs, of which 1 (Sirius B) is more massive than Sun
Looking at the statement "all main sequence stars", I count a grand total of 104 main sequence stars (2A+1F+7G+15K+79M) of which 7 are Sun or brighter than Sun. Almost 7%, more than my estimate but close. I also count 27 off-main-sequence "stars" (21 brown dwarfs and 6 white), so total 131 "stars"... but with the strong suspicion of more late-T, early-Y dwarfs (who can check?). Sun or more massive than Sun is again exactly 7 of them (now excluding Achird A but including Sirius B instead), so almost 95% of stars in solar neighbourhood are less massive than Sun.
But who can check the rest of Milky Way?
 
  • Informative
Likes pinball1970
TL;DR Summary: In 3 years, the Square Kilometre Array (SKA) telescope (or rather, a system of telescopes) should be put into operation. In case of failure to detect alien signals, it will further expand the radius of the so-called silence (or rather, radio silence) of the Universe. Is there any sense in this or is blissful ignorance better? In 3 years, the Square Kilometre Array (SKA) telescope (or rather, a system of telescopes) should be put into operation. In case of failure to detect...
Thread 'Could gamma-ray bursts have an intragalactic origin?'
This is indirectly evidenced by a map of the distribution of gamma-ray bursts in the night sky, made in the form of an elongated globe. And also the weakening of gamma radiation by the disk and the center of the Milky Way, which leads to anisotropy in the possibilities of observing gamma-ray bursts. My line of reasoning is as follows: 1. Gamma radiation should be absorbed to some extent by dust and other components of the interstellar medium. As a result, with an extragalactic origin, fewer...
This hypothesis of scientists about the origin of the mysterious signal WOW seems plausible only on a superficial examination. In fact, such a strong coherent radiation requires a powerful initiating factor, and the hydrogen atoms in the cloud themselves must be in an overexcited state in order to respond instantly. If the density of the initiating radiation is insufficient, then the atoms of the cloud will not receive it at once, some will receive it earlier, and some later. But then there...
Back
Top