Promotion Tabulation

We make a tabulation of a "promotion funnel" in which potential target stars or planets are found, promoted, and characterized. There are two tables, each restricted to a specific target family:

Deep-dive stars: a list of Hipparcos numbers for target stars of special interest, controlled by the top_HIPs script variable. Typically this list is smaller than the list of all promoted stars below.
Promoted stars: a list of stars that have been promoted into a category where they are eligible for spectral characterization. The EXOSIMS scheduler controls promotion, and provides the list at the end of the simulation in the promoted_stars variable.

It is helpful to visualize the table as a funnel, in which stars are promoted to be eligible for spectral characterization (row 1), characterizations are attempted (rows 2 and 3), and some of them succeed (rows 4 and 5).

The same is true of planets: in order to be successfully characterized (last rows) the star around the planet must be promoted (row 1).

All quantities after ± are the standard error of the mean. That is, they are the population standard deviation divided by the square root of ensemble size, so they will drop to zero as ensemble size grows. The ensemble size used for this scaling is shown in a note below the table. The intent is to show how accurate the shown average is.

Table Contents

In all cases, consideration is restricted to a population P of stars (deep-dive or promoted). All quantities in the table are averages across the ensemble.

Column naming. The final column is the earthlike planet class. Its heading follows the name given in the scenario's config-reduce.json, and is "Earth" when nothing is customized -- so a scenario that re-defines the class to, say, a Sub-Neptune population will show "Sub-Neptune" there instead. This page uses the default name throughout.

Below is an example table for an Earths-only scenario as a visual reminder.

Status	Star	Planet	Hab. Zone	Earth
Promoted	19.83 ± 0.38	21.94 ± 0.45	21.94 ± 0.45	21.94 ± 0.45
Attempt: Cume	28.58 ± 1.23	31.85 ± 1.41	31.85 ± 1.41	31.85 ± 1.41
Attempt: Unique	12.72 ± 0.32	14.46 ± 0.38	14.46 ± 0.38	14.46 ± 0.38
Observed: Cume	28.58 ± 1.23	30.37 ± 1.28	30.37 ± 1.28	30.37 ± 1.28
Observed: Unique	12.72 ± 0.32	13.98 ± 0.36	13.98 ± 0.36	13.98 ± 0.36

Row 1: Promoted

Star : How many stars were promoted. If P is promoted stars, this is the ensemble average of len(promoted_stars). If P is deep-dive stars, this will be the ensemble average of the intersection of promoted_stars and the deep-dive list.

Planet : How many planets orbit the promoted stars. See the note below.

Hab. Zone : How many HZ planets orbit the promoted stars.

Earth : How many Earthlike planets orbit the promoted stars. (Named for the earthlike class -- see the note above.)

Note: The planet counts in this row are counting how many planets are around promoted stars. They do not say anything about observing (detecting) any specific planets. In the illustrated case, there was on average about 1.1 planet per promoted star (21.94 planets, 19.83 stars). This is consistent with an "Earths-only" planet population: all promoted stars will have one planet, and some will have two or perhaps three.

This definition follows the "funnel" concept mentioned above. The promotion mechanism has reduced the pool of stars eligible for characterization from the full TargetList to just the promoted stars. Correspondingly, the pool of possible planets is now reduced to that in the right-hand three columns.

Depending on observation scheduling and success, the pool of planets will be reduced further, as seen in the next rows.

Rows 2-3: Attempted Spectral Characterizations

First, the "Attempt: Cume" row.

Star : The ensemble average of the number of attempted spectral characterizations of stars in P. An alternative wording: the average number of characterization visits to stars in P, counting revisits.

Planet : The total number of planets potentially observed by such visits and re-visits, regardless of success. If a star with 8 planets is visited 3 times, this number will increase by 24.

Hab. Zone, Earth : The total number of Habitable Zone (resp. Earthlike) planets potentially observed by such visits, regardless of success.

The "Attempt: Unique" row simply ignores revisits. It may never exceed the above row.

Star : The ensemble average of stars in P with any attempted spectral characterization. Alternatively: the number of stars in P with any characterization visit at all.

Planet, Hab. Zone, Earth : The total number of planets (resp. HZ or Earthlike planets) of stars in P potentially observed by such visits. In the case above where a star with 8 planets is visited 3 times, this number increases by only 8, because revisits are not counted.

Again, the "funnel" concept is evident:

Our efficiency in scheduling the promoted stars is measured by the difference between these rows and the first row. This difference can be denominated in either Stars or Planets.
Observing opportunities spent on revisits are measured by the difference between Cumulative versus Unique attempts.

In the scenario above, we visited about 2/3 of the promoted stars (12.72 visits to 19.83 stars), and we typically revisited stars at least once (28.58 total visits, 12.72 unique visits).

Rows 4-5: Successful Spectral Characterizations

First, the "Observed: Cume" row.

In the descriptions below, "successful characterization" is the generous interpretation: any partial or full spectral characterization, in any band.

Star : The count of all successful spectral characterizations of any planet of a star in P, counting repeat characterizations. An alternative wording is: the count of successful char visits and re-visits to stars in P. (Successful means that at least one planet around that star was characterized.)

Planet, Hab. Zone, Earth : The count of all successful characterizations of planets (resp., HZ or Earthlike planets) of stars in P. In this case, unlike for Attempts, the planet-by-planet success is taken in to account. So in the case above of the star with 8 planets, the particular characterization status of each planet will be added up over all repeat visits.

Again, the "Observed: Unique" row ignores revisits, and it may never exceed the above row.

Star : The count of stars in P with any successful spectral characterization. Alternatively: the count of stars in P with a successful characterization visit.

Planet, Hab. Zone, Earth : The number of planets (resp. HZ or Earthlike planets) of stars in P characterized at least once.

This segment of the "funnel" covers our ability to schedule successful characterizations, e.g., at favorable phase angle and satisfying keepout.