J/A+A/568/A49 Long-term photometry of pre-MS stars (Poljancic Beljan+, 2014)
Long-term photometric observations of pre-main sequence objects in the field of
North America/Pelican Nebula.
Poljancic Beljan I., Jurdana-Sepic R., Semkov E.H., Ibryamov S.,
Peneva S.P., Tsvetkov M.K.
<Astron. Astrophys. 568, A49 (2014)>
=2014A&A...568A..49P 2014A&A...568A..49P
ADC_Keywords: Stars, variable ; Stars, pre-main sequence ; Photometry, UBVRI
Keywords: stars: pre-main sequence - stars: variables: general
Abstract:
To broaden the search and study stars in the early evolutionary phase,
we investigated a sample of 17 pre-main sequence objects previously
detected as either Hα emission-line pre-main sequence stars or
T Tauri variables located in the field of the North America/Pelican
Nebula complex. Johnson-Cousins B, V, Rc, Ic magnitudes and mean color
indices for the program stars are determined from more than 12400
measurements from archive photographic plates and from CCD data
collected at 7 observatories covering the period of almost 60 years
from 1954 up to 2013. We complemented previously rare insights on the
photometry of the program stars and presented their photometric
history, which for almost all program stars is the first long term
photometric monitoring on a timescale of 6 decades. Eight program
stars are found to be classical T Tauri stars of variability type II,
while 6 program stars are weak-line T Tauri stars of variability
type I. For the first time, periodicity is found for three stars:
V1716 Cyg indicates a 4.15 day period, V2051 Cyg indicates a 384 day
period, and V521 Cyg a period of 503 days.
Description:
We carried out a CCD BVRI photometric observational program for 17
stars (finding chart in Fig. 1) in the field of V2493 Cyg ("Gulf of
Mexico"). The star sample was extracted from the SIMBAD astronomical
database.
The observational material comes from (i) the whole photographic plate
stack preserved at Asiago Observatory (Italy) and the National
Astronomical Observatory Rozhen (Bulgaria); from (ii) digitized plates
from the Palomar Schmidt telescope; and (iii) several scanned plates
from the Schmidt telescope of the Byurakan Astrophysical Observatory
(Armenia). The CCD photometric observations were performed with the 2m
RCC, the 50/70cm Schmidt and the 60cm Cassegrain telescopes of the
National Astronomical Observatory Rozhen (Bulgaria) and the 1.3m RC
telescope of the Skinakas Observatory1 of the Institute of Astronomy,
University of Crete (Greece). More observational and technical details
are given in Semkov et al. (2012, Cat. J/A+A/542/A43). All frames were
exposed through a set of standard Johnson-Cousins filters. The time
span covers almost 60 years, from 1954 to 2013; see table 2:
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Observatory/Telescope Medium Nobs Time span
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Asiago Schmidt 67/92 & 40/50 photogr. plates 198 30/08/1962-18/11/1998
Palomar Schmidt photogr. plates 6 5/07/1954-12/09/1994
Byurakan Schmidt 100/130 photogr. plates 6 28/08/1973-22/06/1977
Rozhen Schmidt 50/70 photogr. plates 4 18/06/1980-11/01/1991
Rozhen Schmidt and Cass. CCD 105 29/10/2000-06/03/2013
Skinakas 1.3m CCD 91 14/06/2000-22/09/2012
Rozhen 2m RCC CCD 35 1/06/1997-04/05/2013
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table6.dat 93 17 Mean photometrical magnitudes and corresponding
standard deviations for program stars
table4/* . 17 Photometry measurement data of the 17 stars
table5/* . 17 CCD photometry measurement data of the 17 stars
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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/205 : H-alpha Stars in Northern Milky Way (Kohoutek+ 1997)
V/73 : Emission-Line Stars of the Orion Population (Herbig+ 1988)
J/A+A/542/A43 : V2493 Cyg BVRI long term photometry (Semkov+, 2012)
J/ApJS/193/25 : The NAN complex. II. MIPS observations (Rebull+, 2011)
J/ApJ/697/787 : The NAN complex. I. IRAC observations (Guieu+, 2009)
J/MNRAS/384/1277 : Hα emission line sources from IPHAS (Witham+, 2008)
J/A+A/479/827 : UBVR light curves of weak-line T Tauri stars (Grankin+, 2008)
J/A+A/461/183 : Variability of classical T Tauri (Grankin+, 2007)
J/BaltA/15/483 : Vilnius photometry in LDN 935 (Laugalys+, 2006)
J/A+A/438/769 : PMS stars Proper Motion Catalog (Ducourant+, 2005)
J/A+AS/104/557 : uvby-beta phot. in star-forming regions (Terranegra+ 1994)
Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Name Star name
14- 18 F5.2 mag <Bmag> ? Mean Johnson B-band magnitude
20- 23 F4.2 mag e_<Bmag> ? <Bmag> uncertainty
25- 29 F5.2 mag <Vmag> ? Mean Johnson V-band magnitude
31- 34 F4.2 mag e_<Vmag> ? <Vmag> uncertainty
36- 40 F5.2 mag <Rmag> Mean Cousins R-band magnitude
42- 45 F4.2 mag e_<Rmag> <Rmag> uncertainty
47- 51 F5.2 mag <Imag> Mean Cousins I-band magnitude
53- 56 F4.2 mag e_<Imag> <Imag> uncertainty
58- 63 F6.2 d Per ? Period (column added by CDS)
65- 78 A14 --- T4 Name of the file with photometry in
subdirectory table4
80- 93 A14 --- T5 Name of the file with CCD photometry in
subdirectory table5
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Byte-by-byte Description of file: table4/*
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Bytes Format Units Label Explanations
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1- 10 A10 "date" Obs.date Date of observation in DD/MM/YYYY format
12- 16 A5 "h:m" Obs.time Universal time
18- 19 I2 min tExp ? Exposure time in minutes
21 A1 --- Band [BVIR-] Observed band
22 A1 --- n_Band [*] Note on Band (1)
23 A1 --- l_mag [≥] Limit flag on mag
24- 28 F5.2 mag mag ? Magnitude in Band
30- 33 F4.2 mag e_mag ? rms uncertainty on mag
35- 45 F11.3 d HJD Heliocentric Julian Date
47- 56 A10 --- Emul Emulsion used for photographic plate
58- 63 A6 --- Filt Filter used for photographic plate
65- 72 A8 --- Plate number of the photographic plate in the archive
74- 86 A13 --- Tel Type of telescope where the plate was recorded
88-101 A14 --- Obs Name of observatory where the plate was recorded
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Note (1): * : means that the band emulsion and filter combination used for this
plate does not fit perfectly declared band but is closest approximation to it
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Byte-by-byte Description of file: table5/*
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Bytes Format Units Label Explanations
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1- 11 A11 "date" Date Date of observation YYYY month DD format
13- 21 F9.3 d HJD Heliocentric Julian Day (HJD-2400000)
23- 27 F5.2 mag Imag ? I magnitude
29- 32 F4.2 mag e_Imag ? Error on I magnitude
34- 38 F5.2 mag Rmag ? R magnitude
40- 43 F4.2 mag e_Rmag ? Error on R magnitude
45- 49 F5.2 mag Vmag ? V magnitude
51- 54 F4.2 mag e_Vmag ? Error on V magnitude
56- 60 F5.2 mag Bmag ? B magnitude
62- 65 F4.2 mag e_Bmag ? Error on B magnitude
67- 72 A6 --- Tel Telescope (data on telescope where CCD was
recorded, "Sch" stays for "Schmidt")
74- 78 A5 --- CCD CCD device
79- 93 A15 --- Obs Name of observatory where CCD was recorded
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Acknowledgements:
Rajka Jurdana Sepic, jurdana(at)uniri.hr
(End) Patricia Vannier [CDS] 17-Jun-2014