2026A&A...705A.217K

Query : 2026A&A...705A.217K

2026A&A...705A.217K - Astronomy and Astrophysics, volume 705A217 (2026/1-1)

Exomoon search with VLTI/GRAVITY around the substellar companion HD 206893 B.

KRAL Q., WANG J., KAMMERER J., LACOUR S., MALIN M., WINTERHALDER T., CHARNAY B., PERROT C., HUET P., ABUTER R., AMORIM A., BALMER W.O., BENISTY M., BERGER J.-P., BEUST H., BLUNT S., BOCCALETTI A., BONNEFOY M., BONNET H., BORDONI M.S., BOURDAROT G., BRANDNER W., CANTALLOUBE F., CASELLI P., CHAUVIN G., CHAVEZ A., CHOMEZ A., CHOQUET E., CHRISTIAENS V., CLENET Y., COUDE DU FORESTO V., CRIDLAND A., DAVIES R., DEMBET R., DEXTER J., DRESCHER A., DUVERT G., ECKART A., EISENHAUER F., FORSTER SCHREIBER N.M., GARCIA P., GARCIA LOPEZ R., GARDNER T., GENDRON E., GENZEL R., GILLESSEN S., GIRARD J.H., GRANT S., HAUBOIS X., HENNING T., HINKLEY S., HIPPLER S., HOULLE M., HUBERT Z., JOCOU L., KEPPLER M., KERVELLA P., KREIDBERG L., KURTOVIC N.T., LAGRANGE A.-M., LAPEYRERE V., LE BOUQUIN J.-B., LUTZ D., MAIRE A.-L., MANG F., MARLEAU G.-D., MERAND A., MOLLIERE P., MONNIER J.D., MORDASINI C., MOUILLET D., NASEDKIN E., NOWAK M., OTT T., OTTEN G.P.P.L., PALADINI C., PAUMARD T., PERRAUT K., PERRIN G., PFUHL O., POURRE N., PUEYO L., RIBEIRO D.C., RICKMAN E., RUSTAMKULOV Z., SHANGGUAN J., SHIMIZU T., SING D., STADLER J., STOLKER T., STRAUB O., STRAUBMEIER C., STURM E., TACCONI L.J., VIGAN A., VINCENT F., VON FELLENBERG S.D., WIDMANN F., WOILLEZ J., YAZICI S. (The GRAVITY Collaboration), ABD EL DAYEM K., AIMAR N., BERDEU A., CORREIA C., DEFRERE D., FABRICIUS M., FEUCHTGRUBER H., FOSCHI A., HONIG S.F., JOHARLE S., LAUGIER R., LAI O., LEFTLEY J., LOPEZ B., MILLOUR F., MONTARGES M., MORUJAO N., NOWACKI H., OSORNO J., PETROV R., PETRUCCI P.O., RABIEN S., ROBBE-DUBOIS S., SADUN BORDONI M., SANCHEZ BERMUDEZ J., SANTOS D., SAUTER J., SCIGLIUTO J., SOULEZ F., SUBROWEIT M. and SYKES C.

Abstract (from CDS):

Context. This study presents the first application of high-precision astrometry to search for exomoons around substellar companions, as this field remains largely unexplored.
Aims. We investigate whether the orbital motion of the companion HD 206893 B exhibits astrometric residuals consistent with the gravitational influence of an exomoon or binary planet.
Methods. Using the VLTI/GRAVITY instrument, we monitored the astrometric positions of HD 206893 B and c on short (days to months) and long (yearly) timescales. This enabled us to isolate potential residual wobbles in the motion of component B attributable to an orbiting moon.
Results. Our analysis reveals tentative astrometric residuals in the HD 206893 B orbit. If interpreted as an exomoon signature, these residuals correspond to a candidate (HD 206893 B I) with an orbital period of approximately 0.76 years and a mass of ∼0.4 Jupiter masses. However, the origin of these residuals remains ambiguous and could be due to systematics. Complementing the astrometry, our analysis of GRAVITY R = 4000 spectroscopy for HD 206893 B confirms a clear detection of water, but no CO was found using cross-correlation. We also found that AF Lep b, and β Pic b are the best short-term candidates to look for moons with GRAVITY+.
Conclusions. Our observations demonstrate the transformative potential of high-precision astrometry in the search for exomoons and proves the feasibility of the technique to detect moons with masses lower than Jupiter and potentially down to less than Neptune in optimistic cases. Crucially, further high-precision astrometric observations with VLTI/GRAVITY are essential to verify the reality and nature of this signal and apply this technique to a range of planetary systems.

Abstract Copyright: © The Authors 2026

Journal keyword(s): instrumentation: interferometers - techniques: interferometric - astrometry - planets and satellites: detection

Simbad objects: 25

goto Full paper

goto View the references in ADS

Number of rows : 25
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026 		#notes
1 HD 1160B LM* 00 15 57.26 +04 15 03.7           ~ 41 0
2 V* DH Tau B LM* 04 29 41.66 +26 32 56.5           M9.25 105 1
3 NAME AF Lep b Pl 05 27 04.7633281608 -11 54 03.466002240           ~ 75 0
4 * bet Pic PM* 05 47 17.0876901 -51 03 59.441135 4.13 4.03 3.86 3.74 3.58 A6V 2087 1
5 * bet Pic b Pl 05 47 17.0876901 -51 03 59.441135           ~ 627 1
6 HD 50571 PM* 06 50 01.0151260800 -60 14 56.921260776   6.548 6.098 7.26   F5VFe+0.4 105 0
7 HD 89839b Pl? 10 20 40.5422616216 -53 39 50.736867444           ~ 4 0
8 HD 95086b Pl 10 57 03.0215719872 -68 40 02.449216128           ~ 127 1
9 HD 114783c Pl 13 12 43.7855575272 -02 15 54.130663296           ~ 8 0
10 2MASS J13153094-2649513 BD* 13 15 30.8597827568 -26 49 51.829331165           L5e 52 1
11 * e Vir b Pl 13 16 46.5148594512 +09 25 26.960139646           ~ 127 1
12 HD 116434C BD* 13 24 36.13 -51 30 16.7           L5-7 123 1
13 HD 128311c Pl 14 36 00.5602765558 +09 44 47.454573266           ~ 63 1
14 V* GQ Lup B LM* 15 49 12.05 -35 39 05.1           M9e 165 1
15 HIP 81208Cb Pl? 16 35 13.84 -35 43 28.7           ~ 2 0
16 HD 154345b Pl 17 02 36.4038090379 +47 04 54.764174452           ~ 50 1
17 HD 155555 RS* 17 17 25.5053342232 -66 57 03.732141636 7.795 7.499 6.723   6.39 G5V+K1V 292 1
18 Kepler-1625b Pl 19 41 43.0400811024 +39 53 11.499004176           ~ 89 1
19 Kepler-1708b Pl 19 47 17.7867385560 +43 37 29.427477204           ~ 30 1
20 * b03 Cyg b Pl 20 14 32.0323540824 +36 48 22.700909124           ~ 22 0
21 HD 206893B BD? 21 45 21.9 -12 47 00           ~ 19 0
22 HD 206893c Pl 21 45 21.9052532928 -12 47 00.060804636           ~ 35 0
23 HD 206893 PM* 21 45 21.9052532928 -12 47 00.060804636   7.11 6.67     F5V 143 0
24 HD 218396 El* 23 07 28.7157209544 +21 08 03.310767492   6.21 5.953     F0+VkA5mA5 1285 0
25 * gam Cep b Pl 23 39 20.9104133784 +77 37 56.510781384           ~ 90 1

To bookmark this query, right click on this link: simbad:objects in 2026A&A...705A.217K and select 'bookmark this link' or equivalent in the popup menu