Five TESS sectors leave 6.3% of phases unobserved for a circular central GJ 887 d transit model at 50.77 days and 2.29 Earth radii
Two later TESS sectors do not close all transit phase gaps for the tested GJ 887 d model. We test five public 120-second SPOC light curves. The nominal model has a circular orbit and a central transit. Its period is 50.77 days and its planet radius is 2.29 Earth radii. The stellar mass is 0.495 solar masses and the stellar radius is 0.468 solar radii. With sectors 2, 28, and 69, 39.69% of midpoint phases have no exposure overlap. Addition of sectors 96 and 106 reduces this fraction to 6.32%. Gaps remain at all 301 tested periods from 50.620 to 50.920 days. We also insert transit models into the archived PDCSAP flux before a fixed one-day filter. At the nominal period and radius, five sectors recover 238 of 256 phases for each tested impact parameter. The tests use three impact parameters and require formal box S/N of at least 35 and a matching midpoint. The threshold was chosen after the initial search. It has no calibrated false-alarm rate. The full test has 18,432 rows. The strongest original search peak has a large dip at a sector boundary and weak support in other sectors. It is not a secure transit. The phase fractions are geometric measures, not planet probabilities. The recovery tests follow upstream PDC processing and search at each inserted period. The package preserves source files, hashes, code, figures, results, and reproduction checks.
GJ 887 d · TESS · transit phase coverage · signal recovery · public astronomical data
References
7- usesdoi:10.1051/0004-6361/202554984
The reported period, stellar mass, stellar radius, and estimated planet radius set the test models. The earlier transit search used sectors 2, 28, and 69.
- usesdoi:10.17909/t9-nmc8-f686
Source collection for five public TESS 120-second SPOC light curves. The included manifest fixes their filenames, source URLs, byte counts, and SHA-256 hashes.
- doi:10.1117/1.JATIS.1.1.014003
- usesdoi:10.1117/12.2233418
The analysis uses public light curves from the SPOC pipeline.
- usesdoi:10.1051/0004-6361:20020802
Box least squares is the flux search method, implemented in Astropy 8.0.2.
- usesdoi:10.1086/683602
batman supplies the circular limb-darkened transit models for signal recovery tests.
- A period average reduces the GJ 887 candidate forecast gain under fixed noise assumptions sci:sha256:f44c4414fade1d53edad73d53323c3456a9934e8d657df95e67d1e2ddd7b7c43
Related GJ 887 work on period-dependent radial velocity forecasts. No data or code from that study are used here.
Cited by
4 publicationsPublic catalog entries on Sciscape.
- TESS sectors 1-107 show no new transit of 659 RV planets in their RV-predicted windows; the same search finds 24 of 28 known transiting RV planets; the HD 44219 eclipses come from a neighbour star
- usesFive TESS visits leave 5.41% of phases unobserved for a circular central GJ 357 d model at 55.661 days and 1.5 Earth radii
We use its exposure interval method and its separate treatment of coverage and signal recovery.
- Twelve TESS sectors cover 81.2 to 82.1 percent of phases for circular HD 216520 c models at 154.43 days, 2 Earth radii and impact parameters 0, 0.5 and 0.8
This related study shows how later TESS sectors can reduce phase gaps. Its numerical inputs and code are not used here.
- usesFive TESS sectors recover all 1152 tested circular GJ 887 e transit signals at 0.8 Earth radii near 4.42490 days
We use its selection of five TESS products and their source manifest. Fresh MAST downloads match all five hashes. That study tests the outer planet d. We write new analysis code for planet e.