WE CLAIM:
1. A telescope comprising a fastener plate (1), a primary
mirror (100) carried by a front face (2) of the plate,
and a secondary mirror (200) held facing the primary
mirror by a support (300), the support (300) comprising a
primary sleeve (310) mounted around the primary mirror
(100), a secondary sleeve (320) mounted around the secondary mirror (200), arms (350) connecting the secondary sleeve to the primary sleeve, and mechanical decoupling means for decoupling the secondary mirror
(200) relative to the primary mirror (100), the telescope being characterized in that:
• the secondary sleeve (320) comprises an outer sleeve (321) and an inner sleeve (322) coaxial with the outer sleeve and connected thereto by symmetrically distributed mechanical decoupling elements (323); and
• the secondary mirror (200) is received with clearance in the inner sleeve (322) and is adhesively bonded thereto by means of a structural adhesive; the outer sleeve (321) including first holes (331) and the inner ring including second holes (332), which first and second holes are through holes that are substantially in alignment to permit the insertion of a cannula for injecting adhesive.

2. A telescope according to claim 1, wherein the second hole (332) is stepped so as to form an abutment against pushing the cannula into the second hole, and the second hole is arranged to provide a leaktight connection with the cannula.
3. A telescope according to claim 1 or claim 2, wherein the first holes are made in the vicinity of the arms.
4. A telescope according to any preceding claim wherein the primary sleeve (310) has a margin (311) projecting

from the primary mirror (100) towards the secondary mirror, and the margin is provided with notches (312) .
5. A telescope according to any preceding claim wherein the primary mirror is connected to the plate by fastener elements (10), each having a base (11) fastened to the plate and, opposite from the base, a bearing (12) that is positioned between first and second rear portions (108 and 109) of the primary mirror and that itself receives a third segment (23) of a pin (20) also having first and second segments (21 and 22) that are received respectively in first and second holes (38 and 39) that are formed respectively in the first and second rear portions; in that the third segment is received in the bearing as a sliding fit and is adhesively bonded in the bearing by means of a structural adhesive; and in that the pin is provided with a central channel (25) having a first end opening out into a portion (26) of the pin that is accessible when the pin is in position in the holes in order to receive one end of a cannula for injecting adhesive, and a second end opening out at least into a transverse channel (27) having at least one end opening out into the outside surface of the third segment.
6. A telescope according to claim 5, wherein the second segment (22) is of diameter that is smaller than the third segment (23) and it is connected thereto via a shoulder that forms an abutment against pushing the second segment into the second hole (39).
7. A telescope according to claim 6, wherein the second hole (39) is a through hole.
8. A telescope according to claim 6, wherein the first segment (21) has a diameter greater than the third segment (23).

9. A telescope according to any one of claims 5 to 8,
wherein the second segment (22) includes a recess (40)
facing the bearing (12) in order to avoid any contact
between the bearing and the second segment (109).
10. A telescope according to any one of claims 5 to 9, wherein the sliding fit is of H7g6 or H7g5 type.
11. A telescope according to any one of claims 5 to 10, wherein the first and second portions (108, 109) are separated from each other by a segment of a circular groove (107) centered on the optical axis of the telescope.
12. A telescope according to any preceding claim wherein each arm (350) has a first end (351) adjacent to the primary sleeve (310) and a second end (352) adjacent to the secondary sleeve (320), the first end extending substantially radially relative to the primary sleeve and the second end connecting substantially tangentially to the secondary sleeve.
13. A telescope according to any preceding claim wherein the arms (350) are curved towards the primary mirror (100) .
14. A telescope according to any preceding claim wherein each arm (350) is of cross-section that varies between its ends (351, 352) in such a manner that, for a given force generating stresses in the arm, the stresses are distributed in equivalent manner along the arm.
15. A telescope according to any preceding claim wherein: each arm (350) has a first end (351) adjacent to the primary sleeve (310) and a second end (352) adjacent to the secondary sleeve (320), the first end extending radially relative to the primary sleeve and the second

end extending tangentially relative to the secondary sleeve; the arms are curved towards the primary mirror; and each arm is of cross-section that varies between its ends in such a manner that, for a given force generating stresses in the arm, the stresses are distributed in equivalent manner along the arm.
16. A telescope according to any preceding claim wherein the telescope is of the Cassegrain type and the plate (1) has a rear surface (3) including positioning references for positioning the telescope relative to an image capture device (400) arranged facing the rear face.
17. A telescope according to claim 16, wherein the positioning references are obtained by optical quality machining and comprise a face (51) perpendicular to the optical axis of the telescope in order to form a tilt reference, a central bore (52) in order to form a centering reference, and a concave surface (53) in the form of a spherical cap having a center on the optical axis in order to define a distance for the image capture device (400) relative to the secondary mirror (200).
18. A telescope according to claim 16 or claim 17, wherein the secondary mirror (200) includes a central portion facing the primary mirror (100), which central portion is provided with at least one centering mark for centering the secondary mirror relative to the primary mirror.
19. A telescope according to claim 18, wherein the mark is in the form of a ring centered on the optical axis of the secondary mirror (200) .
20. A telescope according to any preceding claim wherein the bearing (12) is connected to the base by two

connecting rods (13) arranged to form a triangle together with the base (11).
21. A telescope according to claim 20, wherein the connecting rods (13) are made integrally with the bearing (12) and with the base (11), and the connecting rods are arranged to provide mechanical decoupling between the primary mirror (100) and the plate (1) in such a manner as to support the primary mirror, while limiting the creation of any mechanical stresses in the primary mirror.