NGC 6994 – clearly not a physical stellar ensemble
نویسندگان
چکیده
منابع مشابه
NGC 6994 - clearly not a physical stellar ensemble ⋆
The sparse stellar ensemble NGC 6994 = M73 has recently been discussed as a possible remnant of an old open cluster. In order to solve the controversy on the nature of this object we have taken high-resolution spectra of the six brightest stars within 6′ angular distance of its nominal position. These stars are the only obvious member candidates for an eventual cluster or cluster remnant since ...
متن کاملNGC 6994 : an open cluster which is not an open cluster ⋆
We report on CCD photometry in the Johnson B, V and I passbands for 146 stars in a 9 × 9 region around the southern aggregate NGC 6994 (C 2056128), which appears in the Lyng̊a (1987) catalogue of open star clusters. We argue that this object is not really an open cluster, but simply a random enhancement of four bright stars above the background level. This stars sample includes HD 358033 and GSC...
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Agency ABSTRACT We present HST NICMOS photometry of the resolved stellar population in the dwarf irregular galaxy NGC 1569. The color-magnitude diagram (CMD) in the F110W and F160W photometric bands contains ∼2400 stars with a formal photometric error ∼ < 0.1 mag down to m F110W ≈ 23.5 and m F160W ≈ 22.5. The fiducial photometry has a completeness factor higher than 50% down to m F110W ≈ 21.5 a...
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Binocular gaze was measured accurately under natural conditions with the Maryland Revolving Field Monitor to determine how visual-clarity affects gaze-accuracy. The gaze of 3 unrestrained, seated subjects (2 presbyopes and 1 myope) was recorded as they tapped 4 LEDs with a long, narrow rod cemented to a thimble worn on their index fingers. They wore positive contact lenses, permitting very clea...
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We have obtained V and I-band photometry for about 17500 stars in the field of the dwarf irregular galaxy NGC 3109, located in the outskirts of the Local Group. The photometry allows us to study the stellar populations present inside and outside the disk of this galaxy. From the VI color-magnitude diagram we infer metallicities and ages for the stellar populations in the main body and in the ha...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2002
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20011730