PREFIX irods:       <http://www.irods.org/ontologies/2013/2/iRODS.owl#> 
PREFIX skos:    <http://www.w3.org/2004/02/skos/core#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
SELECT ?x ?absPath ?size ?created 
WHERE { 

?x  irods:correspondingConcept <http://purl.org/astronomy/uat#T1754> .
?x irods:absolutePath ?absPath .
?x irods:createDate ?created .

OPTIONAL { 
?x irods:hasSizeInBytes ?size
}
}