J/ApJS/190/203 3.6 years of DIRBE NIR stellar light curves (Price+, 2010)
3.6 years of DIRBE near-infrared stellar light curves.
Price S.D., Smith B.J., Kuchar T.A., Mizuno D.R., Kraemer K.E.
<Astrophys. J. Suppl. Ser., 190, 203-219 (2010)>
=2010ApJS..190..203P 2010ApJS..190..203P
ADC_Keywords: Photometry, infrared ; Stars, variable
Mission_Name: COBE
Keywords: catalogs - infrared: stars - stars: AGB and post-AGB -
stars: variables: general
Abstract:
The weekly averaged near-infrared fluxes for 2652 stars were extracted
from the cold and warm era all-sky maps of the Diffuse Infrared
Background Experiment (DIRBE). Since the DIRBE program only archived
the individual Calibrated Infrared Observations for the 10 month cold
era mission, the weekly averaged fluxes were all that were available
for the warm era. The steps required to extract stellar fluxes are
described as are the adjustments that were necessary to correct the
results for several systematic effects. The observations are at a
cadence of once a week for 3.6 years (∼1300 days), providing
continuous sampling on variable stars that span the entire period for
the longest fundamental pulsators. The stars are divided into three
categories: those with large amplitude of variability, smaller
amplitude variables, and sources whose near-infrared brightness do not
vary according to our classification criteria. We show examples of the
results and the value of the added baseline in determining the phase
lag between the visible and infrared.
Description:
The COBE satellite was developed by NASA's Goddard Space Flight Center
to measure the diffuse infrared and microwave radiation from the early
universe to the limits set by our astrophysical environment. It was
launched November 18, 1989 and carried three instruments including the
Diffuse Infrared Background Experiment (DIRBE) to search for the
cosmic infrared background radiation.
The DIRBE (described in 1993SPIE.2019..180S 1993SPIE.2019..180S) 1.25, 2.2, 3.5, and 4.9um
near-infrared bands did obtain data for another ∼2.7 years after the
initial 10 month cold (cryogenic) phase (1989 November to 1990
September).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 117 518 DIRBE variables
table2.dat 117 79 DIRBE candidate variables
table3.dat 101 2055 DIRBE non-variables
lc/* . 10347 *Light curves files of sources
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Note on lc/*: Light curve file names are composed of the DIRBE object name,
which is based on the 2MASS counterpart, plus the band. Bands are denoted as
1_25, 2_2, 3_5, and 4_9. The lengths of the light curve files range from
50 to 185 measurements. Note that not all stars have data in all 4 bands.
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See also:
J/ApJ/500/554 : COBE DIRBE IR photometry (Odenwald+ 1998)
J/ApJS/154/673 : COBE DIRBE Point Source Catalog (Smith+, 2004)
http://lambda.gsfc.nasa.gov/product/cobe/dirbe_prod_table.cfm : DIRBE data
home page.
Byte-by-byte Description of file: table[12].dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- DIRBE DIRBE name (G1)
19- 34 A16 --- Name Star name (G2) (1)
36- 40 I5 Jy F1.25 ? Average DIRBE 1.25 micron flux density
42- 45 I4 d P1.25 ? Period of the 1.25 micron light curve
47- 50 I4 Jy A1.25 ? Amplitude of the 1.25 micron light curve (2)
52- 54 I3 --- o_F1.25 ? Number of 1.25 micron observations (3)
56- 60 I5 Jy F2.2 ? Average DIRBE 2.2 micron flux density
62- 65 I4 d P2.2 ? Period of the 2.2 micron light curve
67- 70 I4 Jy A2.2 ? Amplitude of the 2.2 micron light curve (2)
72- 74 I3 --- o_F2.2 ? Number of 2.2 micron observations (3)
76- 80 I5 Jy F3.5 ? Average DIRBE 3.5 micron flux density
82- 85 I4 d P3.5 ? Period of the 3.5 micron light curve
87- 90 I4 Jy A3.5 ? Amplitude of the 3.5 micron light curve (2)
92- 94 I3 --- o_F3.5 ? Number of 3.5 micron observations (3)
96- 99 I4 Jy F4.9 ? Average DIRBE 4.9 micron flux density
101-104 I4 d P4.9 ? Period of the 4.9 micron light curve
106-108 I3 Jy A4.9 ? Amplitude of the 4.9 micron light curve (2)
110-112 I3 --- o_F4.9 ? Number of 4.9 micron observations (3)
114-117 A4 --- Com [ABCF, ] Additional comment(s) (G3)
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Note (1): In original data of table 2, IRAS 02781-02115 is a misprint for
GSC 02781-02115.
Note (2): As many objects are semi-regular or irregular variables, "amplitude"
was defined by averaging the 3 data points centered the data minimum
and maximum and taking half the difference. Periods of greater than
∼1100 days were not fully sampled by the DIRBE observations and
therefore should be considered tentative unless confirmed by other
data.
Note (3): Objects with fewer than 50 data points in a band have only the number
of data points reported.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- DIRBE DIRBE name (G1)
19- 41 A23 --- Name Other name (G2)
44- 48 I5 Jy F1.25 ? Average DIRBE 1.25 micron flux density
50- 52 I3 Jy e_F1.25 ? The 1σ uncertainty in F1.25
54- 56 I3 --- o_F1.25 ? Number of 1.25 micron observations
58- 62 I5 Jy F2.2 ? Average DIRBE 2.2 micron flux density
64- 66 I3 Jy e_F2.2 ? The 1σ uncertainty in F2.2
68- 70 I3 --- o_F2.2 ? Number of 2.2 micron observations (1)
72- 75 I4 Jy F3.5 ? Average DIRBE 3.5 micron flux density
77- 79 I3 Jy e_F3.5 ? The 1σ uncertainty in F3.5
81- 83 I3 --- o_F3.5 ? Number of 3.5 micron observations (1)
85- 88 I4 Jy F4.9 ? Average DIRBE DIRBE 4.9 micron flux density
90- 92 I3 Jy e_F4.9 ? The 1σ uncertainty in F4.9
94- 96 I3 --- o_F4.9 ? Number of 4.9 micron observations (1)
98-101 A4 --- Com [ABCF, ] Additional comment(s) (G3)
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Note (1): Objects with fewer than 50 data points in a band have only the number
of data points reported.
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Byte-by-byte Description of the files: lc/*
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Bytes Format Units Label Explanations
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2- 4 I3 --- Week [4,189] Week number
(starts on JD2447875 = 1989-11-23 12:00UT)
9-15 F7.2 d JD JD-2440000 (approximate)
20-27 F8.2 Jy Flux Corrected flux density
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Global notes:
Note (G1): DIRBE names are the letter "D" with the 2MASS position in the
format hhmmss.ssAddmmss.s where A=[P,M] for positive and negative
declinations, respectively, as in the DIRBE Point Source Catalog
(Smith et al. 2004, Cat. J/ApJS/154/673)
Note (G2): Common names are from a SIMBAD search. Over 99% of the sources
had a single match within 10". For one source, D05094580P2301269, the
corresponding 2MASS, RAFGL, and IRC sources seem to have been
mis-identified in SIMBAD with TYC 1846-1777-1 rather than TYC 1845-3616-1.
Note (G3): Flags in the Comments column are:
A = Star selected by the 4.9um criteria without the variability flag;
B = Star selected by the 4.9um criteria with the variability flag;
C = Star from the AFRL calibration network;
F = there are confusion flags in the DIRBE Point Source Catalog
(Smith et al. 2004, Cat. J/ApJS/154/673).
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History:
From Kathleen Kraemer, Kathleen.Kraemer(at)hanscom.af.mil
(End) Kathleen Kraemer [USAF], Emmanuelle Perret [CDS] 03-Aug-2010