J/AJ/152/104 New photometrically variable magnetic CP stars (Hummerich+, 2016)
New photometrically variable magnetic chemically peculiar stars in the ASAS-3
archive.
Hummerich S., Paunzen E., Bernhard K.
<Astron. J., 152, 104-104 (2016)>
=2016AJ....152..104H 2016AJ....152..104H (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Stars, peculiar ; Spectral types
Keywords: stars: chemically peculiar - stars: individual (V414 Pup) -
stars: rotation - stars: variables: general
Abstract:
The magnetic Ap or CP2 stars are natural atomic and magnetic
laboratories. Strictly periodic changes are observed in the spectra
and brightness of these stars, which allow the derivation of
rotational periods. Related to this group of objects are the He-weak
(CP4) and He-rich stars, some of which also undergo brightness changes
due to rotational modulation. Increasing the sample size of known
rotational periods among CP2/4 stars is important and will contribute
to our understanding of these objects and their evolution in time. We
have compiled an extensive target list of CP2/4 stars from the General
Catalog of Ap, HgMn, and Am stars, including several early-type
(spectral types B/A) variables of undetermined type from the
International Variable Star Index. We investigated our sample stars
using publicly available observations from the ASAS-3 archive. Our
previous efforts in this respect led to the discovery of 323 variable
stars. Using a refined analysis approach, we were able to identify
another 360 stars exhibiting photometric variability in ASAS-3 data.
Summary data, folded light curves and, if available, information from
the literature are presented for our final sample, which is composed
of 334 bona-fide α2 Canum Venaticorum (ACV) variables, 23 ACV
candidates, and 3 eclipsing binary systems. Interesting and unusual
objects are discussed in detail. In particular, we call attention to
HD66051 (V414 Pup), which is an eclipsing binary system showing
obvious rotational modulation of the light curve due to the presence
of an ACV variable in the system.
Description:
The All Sky Automated Survey (ASAS) constantly monitored the entire
southern sky and part of the northern sky to about δ<+28°.
The third phase of the project, ASAS-3, lasted from 2000 until 2009
(Pojmanski 2002, Cat. II/264).
The employed instrumentation, which was situated at the 10inch
astrograph dome of the Las Campanas Observatory in Chile, consisted of
two wide-field telescopes equipped with f/2.8 200mm Minolta lenses and
2048*2048 AP 10 Apogee detectors that covered a field of sky of
8.8°*8.8°. About 107 sources brighter than V∼14mag were
monitored in Johnson V. The achieved CCD resolution was about
14.8''/pixel, which led to an astrometric accuracy of around 3''-5''
for bright stars and up to 15.5'' for fainter stars.
An initial list of target stars was created by selecting CP2 stars or
CP2 star (the magnetic Bp/Ap stars) candidates and He-weak
(CP4)/He-strong objects from the most recent version of the Catalog of
Ap, HgMn, and Am stars (Renson & Manfroid 2009, Cat. III/260).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 149 360 Essential data for the stars identified as
photometrically variable Chemically Peculiar
(CP) stars or candidates
table3.dat 343 99 Relevant information on single objects from the
literature and miscellaneous remarks
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See also:
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
III/260 : General Catalogue of Ap and Am stars (Renson+ 2009)
I/280 : All-sky Compiled Catalogue of 2.5 million stars (Kharchenko+ 2009)
II/264 : ASAS Variable Stars in Southern hemisphere (Pojmanski+, 2002-2005)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
II/97 : ANS UV Catalogue of Point Sources (Wesselius+ 1982)
J/A+A/581/A138 : Photometric variability in CP stars (Bernhard+, 2015)
J/AN/336/590 : Bochum Galactic Disk Survey: II (Hackstein+, 2015)
J/MNRAS/427/2917 : Classification of Hipparcos variables (Rimoldini+, 2012)
J/MNRAS/420/757 : STEREO magnetic chemically peculiar stars (Wraight+, 2012)
J/A+A/525/A16 : Light curves of CP stars in open clusters (Paunzen+, 2011)
J/other/IBVS/5480 : Elements for 80 eclipsing binaries (Otero, 2003)
J/MNRAS/331/45 : New periodic variables (Koen+, 2002)
http://www.astrouw.edu.pl/asas/ : ASAS website
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Primary identifier (HD number, or other
conventional identification)
17- 21 I5 --- RM09 [760/58310]? Identification number in Renson &
Manfroid 2009 (Cat. III/260)
23- 24 I2 h RAh Hour of Right Ascension (J2000) (1)
26- 27 I2 min RAm Minute of Right Ascension (J2000) (1)
29- 33 F5.2 s RAs Second of Right Ascension (J2000) (1)
35 A1 --- DE- Sign of the Declination (J2000) (1)
36- 37 I2 deg DEd Degree of Declination (J2000) (1)
39- 40 I2 arcmin DEm Arcminute of Declination (J2000) (1)
42- 45 F4.1 arcsec DEs Arcsecond of Declination (J2000) (1)
47- 52 A6 --- Type Variability type (ACV, ACV:, or EA) (2)
54- 58 F5.2 --- Vmax [6.4/12] Brightest V band magnitude (3)
60- 64 F5.2 --- Vmin [6.4/11.7] Faintest V band magnitude (3)
66- 75 F10.6 d Per [0.5/265.1] Period
77- 84 F8.6 d e_Per [0/0.4] Uncertainty in Period
86- 93 F8.3 d Epoch [1873/5144.7] Epoch in Heliocentric Julian Date
(HJD-2450000) (4)
95- 99 F5.3 d e_Epoch [0.005/0.9] Uncertainty in Epoch
101-105 F5.3 mag Amp1 [0.002/0.037]? Fundamental sine wave
semi-amplitude (A1) (5)
107-111 F5.3 mag Amp2 [0/0.036]? Semi-amplitude of the first harmonic
variation (A2) (5)
113-117 F5.3 rad Phase1 [0/1]? Fundamental sine wave phase (φ1) (5)
119-123 F5.3 rad Phase2 [0/1]? Phase of the first harmonic variation
(φ2) (5)
125-135 A11 --- SpT Spectral type (6)
137-142 F6.3 mag B-V [-0.16/0.65]? The (B-V) color index (7)
144-149 F6.3 mag J-Ks [-0.17/0.26] The (J-Ks) color index (8)
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Note (1): From Tycho-2 catalog (Cat. I/259).
Note (2): Variability type, according to GCVS (Cat. B/gcvs) convention:
EA = Eclipsing binary system of Algol-type;
ACV = bona-fide α2 Canum Venaticorum variable;
ACV: = ACV candidate.
Note (3): As derived from Fourier fit to the ASAS-3 (Pojmanski et al.,
Cat. II/264) data.
Note (4): Time of maximum is indicated for α2 Canum Venaticorum (ACV)
variables or candidates, time of minimum for the eclipsing binary systems.
Note (5): Calculated only for α2 Canum Venaticorum (ACV) variables or
candidates. In the case of HD66051 (V414 Pup), the corresponding values
have been calculated from a fit to the out-of-eclipse, rotationally induced
variability (see Section 4.2.2). The calculation of the phase values has
been based on the times of observations as provided by the ASAS-3 database,
i.e., HJD-2450000.
Note (6): As listed in Renson & Manfroid 2009 (Cat. III/260); it is noteworthy
that, as in the original catalog, the "p" denoting peculiarity has been
omitted from the spectral classifications taken from Renson & Manfroid 2009
(Cat. III/260). For the five stars not included in this catalog, the
spectral types have been gleaned from the VSX (Cat. B/vsx) and verified
using the VizieR and SIMBAD catalog services.
Note (7): Taken from Kharchenko 2001 (Cat. I/280).
Note (8): As derived from the 2MASS catalog (Cat. II/246).
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Star name (HD number, or other conventional
identification)
17- 35 A19 --- LName Variable star designation from the literature
37- 48 A12 --- VType Variable star type from the literature
50- 59 F10.6 d LPer1 [0.7/310]? First period from the literature
61 A1 --- u_LPer1 [?] Uncertainty flag on Per1
63- 72 A10 --- n_LPer1 Note on Per1
74- 77 A4 --- r_LPer1 Reference for Per1 (1)
79- 86 F8.6 d LPer2 [0.3/3.9]? Second period from the literature
88- 90 A3 --- r_LPer2 Reference for LPer2 (1)
92-101 F10.6 d WPer [0.6/265.1]? Period from this work
103-110 F8.6 d e_WPer [5e-06/0.4]? Error in WPer
112-115 A4 --- Ref Reference in which, to the best of our
knowledge, the object has been announced
as a variable star for the first time (1)
117 A1 --- Flag [*] Doubtful chemically peculiar object (2)
119-343 A225 --- Com Remarks/Comments
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Note (1): The reference codes are defined as follows:
D11 = Dubath et al. 2011 (Cat. J/MNRAS/414/2602);
F08 = Freyhammer et al. 2008MNRAS.389..441F 2008MNRAS.389..441F;
GCVS = Samus et al. (General Catalogue of Variable Stars, Cat. B/gcvs);
H15 = Hackstein et al. 2015 (Cat. J/AN/336/590);
H77 = Hrivnak 1977IBVS.1293....1H 1977IBVS.1293....1H;
K08 = Kochukhov et al. 2008A&A...479L..29K 2008A&A...479L..29K;
K91 = Kornilov et al. 1991TrSht..63....1K 1991TrSht..63....1K;
KE02 = Koen & Eyer 2002 (Cat. J/MNRAS/331/45);
O03 = Otero 2003 (Cat. J/other/IBVS/5480);
P11 = Paunzen et al. 2011 (Cat. J/A+A/525/A16);
R12 = Rimoldini et al. 2012 (Cat. J/MNRAS/427/2917);
RB82 = Rufener & Bartholdi 1982A&AS...48..503R 1982A&AS...48..503R;
RM09 = Renson and Manfroid 2009 (Cat. III/260);
SP14 = Sitek & Pojmanski 2014AcA....64..115S 2014AcA....64..115S;
VF79 = Vogt & Faundez 1979A&AS...36..477V 1979A&AS...36..477V;
vL97 = van Leeuwen et al. 1997 (Cat. I/239);
VSX = Watson et al. (AAVSO International Variable Star Index VSX,
Cat. B/vsx);
W12 = Wraight et al. 2012 (Cat. J/MNRAS/420/757);
W82 = Wesselius et al. 1982 (Cat. II/97).
Note (2): An asterisk denotes stars whose status as chemically peculiar objects
is doubtful according to Renson and Manfroid 2009 (Cat. III/260).
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 28-Oct-2016