discov_num |
notes |
refcode |
GAA 2 |
AW Per. This Cepheid is an SB with an orbital period of ~40 yr. First |
|
|
discovered by Miller & Preston (1964 PASP 76, 47), it took several |
|
|
years to derive the first orbit from radial velocity data (Evans 1989 |
|
|
AJ 97, 1737). It is likely that this companion is itself a binary, as |
|
|
argued by Evans and by Evans et al. (2000 AJ 120, 407), because the |
|
|
magnitude difference between the Cepheid and its companion is not |
|
|
consistent with equal masses and predictions from evolutionary tracks. |
|
|
Unfortunately, Gallenne et al. (2015) note they did not have enough |
|
|
angular resolution and sensitivity to detect this third companion. The |
|
|
properties of the brightest companion were studied based on IUE |
|
|
spectra by Evans (1994 ApJ 436, 273; 1995 ApJ 445, 393), who found its |
|
|
spectral type to be B8.3V. This is in agreement with their detection |
|
|
with a flux ratio f = 1.22 +/- 0.30%, i.e., a spectral type in the |
|
|
range B6-B9V (using d = 853 pc from a P-L relation and K = 4.63 mag |
|
|
for the Cepheid). They estimate the companion mH = 9.6 +/- 0.3 mag |
|
|
(using for the Cepheid at theirgiven phase mH = 4.84 +/- 0.01 mag from |
|
|
Monson & Pierce (2011 ApJS 193, 12). Massa & Evans (2008 MNRAS 383, |
|
|
139) also determined the angular separation of the component for |
|
|
another epoch, which will allow an estimate all the orbital elements, |
|
|
(see also Gallenne et al. 2013 EAS Pub. Ser. 64, 197). Gallenne et al. |
|
|
(2015) derived a maximum sensitivity limit at 3sigma of 0.62%, i.e., |
|
|
dmH> 5.5 mag, so can therefore exclude any additional components with |
|
|
a spectral type earlier than B9V. |
GaA2015 |
|
Spectroscopic binary orbit with P = 13954d determined. |
Grf2016c |
refcode |
metd |
author |
reference |
GaA2015 |
Kv j |
Gallenne, A., Merand, A., Kervella, P., Monnier, J.D., Schaefer, G.H., Baron, F., |
2015A&A...579A..68G |
GaA2015 |
+Kc |
Breitfelder, J., Le Bouquin, J.-B., Roettenbacher, R.M., Gieren, W., |
|
GaA2015 |
|
Pietrzynski, G., McAlister, H., et al. |
|
GaA2015 |
|
A&A 579, A68, 2015 |
|
Grf2016c |
not - |
Griffin, R.F. |
2016Obs...136..209G |
Grf2016c |
|
Observatory 136, 209, 2016 |
|
idgroup |
discov |
author |
1 |
KRV |
Kervella, P., Thevenin, F., & Petr-Gotzens, M.G. |
10 |
KRV |
Kervella, P., Gallenne, A., Evans, N.R., Szabados, L., Arenouu, F., Merand, A., |
10 |
KRV |
Proto, Y., Karczmarek, P., Nardetto, N., Gieren, W. & Pietrzynski, G. |
11 |
KRV |
Kervella, P., Gallenne, A., Evans, N.R., Szabados, L., Arenouu, F., Merand, A., |
11 |
KRV |
Nardetto, N., Gieren, W. & Pietrzynski, G. |
13 |
KRV |
Kervella, P., Borgniet, S., de Souza, A.D., Merand, A., Gallenne, A., Rivinius, T., |
13 |
KRV |
Lacour, S., Carciofi, A., Faes, D.M., Le Bouquin, J.-B., Taormina, M., Pilecki, B., |
13 |
KRV |
Berger, J.-P., Bendjoya, P., Klement, R., Millour, F., Janot-Pacheco, E., Spang, A. |