Scalar particles might be in the universe as diffuse gaseous clouds or compact objects and might be even present in D-stars. The astrophysical consequences are discussed in detail. Especially, D-stars may be considered as an elegant candidate. The Einstein ring should be observable with MAXIM if D-stars exist. PACS:  04. 20. Jb, 04. 80. -y, 95. 30. Sf, 98. 80. Cq