J/ApJ/541/841 UBV photometry and ages of Trapezium systems (Abt+, 2000)
The maximum age of Trapezium systems.
Abt H.A., Corbally C.J.
<Astrophys. J. 541, 841 (2000)>
=2000ApJ...541..841A 2000ApJ...541..841A
ADC_Keywords: Stars, double and multiple ; Photometry, UBV ; Reddening ;
Stars, distances
Keywords: binaries: visual - open clusters and associations: general -
stars: fundamental parameters
Abstract:
We sought to determine the maximum age of Trapezium systems by
studying possible trapezium systems that were selected independently
of their occurrence in H II regions. We started with the unpublished
catalog by Allen, Tapia & Parrao (1977RMxAA...3..119A 1977RMxAA...3..119A) of all the
known visual systems having three or more stars in which the maximum
separation is less than 3.0 times the minimum separation. Their
catalog has 968 such systems whose most frequent primary type is F,
which does not describe young systems. With a CCD on the Kitt Peak
0.9m telescope we obtained UBV frames for 265 systems accessible with
our equipment on Kitt Peak. The frames were used to obtain UBV
photometry for about 1500 stars with an accuracy of 0.04mag between
V=7 and 14mag. Also these frames were used to obtain astrometry with
an accuracy of ±0.015° in position angle and ±0.01" in
separation. For the brightest star in each system we obtained a
spectral type to determine the distance and reddening to the system.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3a.dat 84 265 Conclusions about the Possible Trapezium Systems
table3b.dat 125 1592 Observational Data
trap.dat 153 310 *Accurate positions and remarks, by B. Skiff
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Note on trap.dat: file added in August 2010, from B. Skiff
(see the "History" section below)
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See also:
I/134 : Trapezium Multiple Systems (Salukvadze, 1978)
Byte-by-byte Description of file: table3a.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [Trap]
5 A1 --- n_Trap [*] indicates corrections made at CDS (see
the "History" section below)
6- 8 I3 --- Trap Trapezium system number ([AC2000b] Trap NNN)
11- 12 I2 h RAh Right Ascension (1900)
14- 17 F4.1 min RAm Right Ascension (1900)
19 A1 --- DE- Sign on the Declination (1900)
20- 21 I2 deg DEd Declination (1900)
23- 24 I2 arcmin DEm Declination (1900)
26- 37 A12 --- OName Other name (ADS ... = no ADS name)
38 A1 --- u_OName [?] For Trap 237, the HD identification
doesn't match the position
40- 67 A28 --- Concl Conclusions about the group
69- 73 F5.2 mag E(B-V) ? Reddening
75 A1 --- f_E(B-V) [:?A] Flag on E(B-V) (1)
79- 82 F4.1 mag DMod ? Distance modulus
84 A1 --- f_DMod [?A] Flag on DMod (1)
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Note (1): Flags have the following meaning:
: = uncertain value
? = unknown value
A = refers to star 'A'
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Byte-by-byte Description of file: table3b.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [Trap]
6- 8 I3 --- Trap Trapezium system number ([AC2000b] Trap NNN)
10- 11 I2 --- ID1 Identification number for Figure 1
13- 14 A2 --- ID2 Identification letter from other sources
16- 20 F5.2 mag Vmag ? V band magnitudes
22- 26 F5.2 mag B-V ? B-V color
28- 32 F5.2 mag U-B ? U-B color
34- 51 A18 --- MKClass MK classification
53- 56 I4 yr date0 Date of earlier astrometric measurements
58- 61 I4 yr date1 ? If present, indicates measurements obtained
from date0 to date1
63- 67 A5 --- n_sep0 ? Star pair that sep0 and pa0 refer
68- 73 F6.2 arcsec sep0 ? Old angular separation relative to
the first star
75 A1 --- f_sep0 [v:] Flag on sep0 (1)
77- 81 F5.1 deg pa0 ? Previous position angle relative to
the first star
83- 85 A3 --- f_pa0 [v orb] Flag on OPA (1)
87- 94 F8.3 yr Date Date of observations from this work
96- 99 A4 --- n_sep ? Star pair that sep and PA refer
102-107 F6.2 arcsec sep ? This work's angular separation relative
to the first star
110-115 F6.2 deg PA ? This work's position angle relative
to the first star
117-125 A9 --- Concl Conclusions about the physical association
of each component
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Note (1): Flags mean the following:
v = variable
: = uncertain measurement
orb = orbit
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Byte-by-byte Description of file: trap.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [Trap]
6- 8 I3 --- Trap Trapezium system number ([AC2000b] Trap NNN)
11- 12 I2 h RA1900.h Right Ascension (1900)
14- 17 F4.1 min RA1900.m Right Ascension (1900)
19 A1 --- DE1900.- Sign on the Declination (1900)
20- 21 I2 deg DE1900.d Declination (1900)
23- 24 I2 arcmin DE1900.m Declination (1900)
26- 37 A12 --- Name Name of the system (ADS ... = no ADS name)
42- 56 A15 --- OName Other designation
59- 60 I2 h RAh Right Ascension J2000 (hours)
62- 63 I2 min RAm Right Ascension J2000 (minutes)
65- 69 F5.2 s RAs Right Ascension J2000 (seconds)
71 A1 --- DE- Declination J2000 (sign)
72- 73 I2 deg DEd Declination J2000 (degrees)
75- 76 I2 arcmin DEm Declination J2000 (minutes)
78- 81 F4.1 arcsec DEs Declination J2000 (seconds)
83 A1 --- s [MTU] Source of position (1)
85- 89 F5.2 mag Vmag Visual magnitude
92-106 A15 --- SpType MK Spectral classification
111-153 A43 --- Remarks Remarks, from B. Skiff
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Note (1): the source of the position is:
M = 2MASS (II/246), T = Tycho-2 (I/259), U = UCAC2 -I/289)
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History:
* 05-Dec-2000: From ApJ electronic version
* 23-Jun-2005: Positions corrected in table3a for Trap 29, 55, 93, 164, 562
(comm. C. Brunet, CDS)
* 24-Aug-2010: other position errors in Trap 630 + 864;
file "trap.dat" with accurate positions added.
(prepared by B. Skiff, Lowell Obs.).
(End) Greg Schwarz [AAS], Patricia Bauer & Francois Ochsenbein [CDS] 05-Dec-2000