COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 2166 Konkoly Observatory Budapest 1982 June 21 HU ISSN 0374-0676 uvby PHOTOMETRY OF THE ALGOL VARIABLE HD 224113 The Algol nature of HD 224113 = HR 9049 (B5V, V=6.08, B-V=-.09) was discovered by Haefner (1981). From uvby photometry obtained in 1970 he derived a value for the orbital period of 2.445088d. The incomplete lightcurve reveals reflection or ellipticity effects, and evidence of gas streams may be present. We here present in tabular form a sequence of 4-colour measurements obtained at the Danish 50cm telescope on La Silla in October 1981. The measurements have been obtained in a differential way, using two comparison stars: C_1 HD 224112 V=6.84 B-V=-.09 A C_2 HD 223352 V=4.57 B-V=.01 A0V The star was measured repeatedly during 8 nights between Oct. 9 and Oct. 18 1981. Table I gives heliocentric Julian dates, and differences between HD 224113 and HD 224112 (V=6.84, b-y=-.032, m_1=.116, c_1=.670) in the standard system of Crawford et al. (1970). The mean error on one single differential measurement in DeltaV, Delta(b-y), Deltam_1 and Deltac_1 are resp. .0027, .0028, .0039 and .0040 magnitudes. The steep decline visible in V on JD2444896 (.1 magnitude in about 80 minutes) represents part of the descending branch of the primary minimum. The dispersion of the DeltaV-values outside eclipse exceeds two times the statistical mean error on one measurement as deduced from the differences between the comparison star measurements. This scatter is due to Proximity effects. JD 2444800 DeltaV delta(b-y) deltam_1 Deltac_1 JD 2444800 deltaV delta(b-y) deltam_1 Deltac_1 87.6190 -.749 -.007 -.008 -.116 92.5474 -.746 -.003 -.014 -.109 87.6429 -.751 -.008 -.005 -.115 92.5628 -.747 -.004 -.011 -.112 88.5648 -.750 -.007 -.005 -.117 92.5790 -.746 -.007 -.007 -.110 88.5862 -.752 -.004 -.012 -.115 92.5893 -.744 -.008 -.007 -.110 88.6137 -.751 -.008 -.004 -.119 92.5982 -.746 -.006 -.008 -.111 88.6273 -.749 -.007 -.009 -.117 95.5363 -.744 -.004 -.014 -.113 88.6443 -.748 -.008 -.006 -.121 95.5514 -.745 -.007 -.008 -.116 89.5439 -.741 -.002 -.014 -.113 95.5662 -.751 -.003 -.013 -.111 89.5685 -.745 -.002 -.011 -.113 95.5804 -.743 -.008 -.006 -.112 89.5818 -.742 -.006 -.009 -.107 95.5945 -.745 -.009 -.004 -.112 89.5912 -.742 -.004 -.011 -.115 95.6394 -.748 -.008 -.003 -.118 90.5430 -.738 -.006 -.009 -.106 95.6589 -.748 -.007 -.006 -.117 90.5567 -.742 -.006 -.008 -.107 95.6750 -.747 -.006 -.010 -.112 90.5721 -.743 -.007 -.011 -.104 95.6898 -.750 -.005 -.010 -.116 90.5870 -.744 -.003 -.013 -.107 95.7075 -.749 -.003 -.013 -.116 90.5993 -.742 -.008 -.007 -.109 96.5404 -.629 -.003 -.011 -.110 91.5467 -.735 +.000 -.017 -.109 96.5540 -.598 -.003 -.005 -.113 91.5642 -.735 -.004 -.007 -.116 96.5702 -.562 -.008 -.000 -.112 91.5754 -.734 -.004 -.011 -.110 96.5863 -.544 -.000 -.010 -.115 91.5851 -.736 -.003 -.007 -.112 96.5969 -.533 -.004 -.005 -.112 91.5980 -.729 -.005 -.006 -.114 C. STERKEN Astrophysical Institute, Vrije Universiteit Brussel References: Crawford, D.L., Barnes, J.V., Golson, J.C. 1970, Astron.J. 75, 624 [BIBCODE 1970AJ.....75..624C ] Haefner, R. 1981, Comm. 27, IAU Inf. Bull. Var. Stars No. 1996. [From IBVS 2187] CORRIGENDUM In I.B.V.S. No. 2166 the 2nd sentence "From uvby photometry obtained in 1970 ..." should read "From uvby photometry obtain- ed in 1978, 1979 and 1980 ...". C. STERKEN