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Title: VARIABILITY IN PROTO-PLANETARY NEBULAE. III. LIGHT CURVE STUDIES OF MAGELLANIC CLOUD CARBON-RICH OBJECTS

Abstract

We have investigated the light variability in a sample of 22 carbon-rich post-AGB stars in the LMC and SMC, based primarily on photometric data from the Optical Gravitational Lensing Experiment survey. All are found to vary. Dominant periods are found in eight of them; these periods range from 49 to 157 days, and most of these stars have F spectral types. These eight are found to be similar to the Milky Way Galaxy (MWG) carbon-rich proto-planetary nebulae (PPNs) in several ways: (a) they are in the same period range of ∼38 to ∼160 days, (b) they have similar spectral types, (c) they are (all but one) redder when fainter, (d) they have multiple periods, closely spaced in time, with an average ratio of secondary to primary period of ∼1.0, and as an ensemble, (e) they show a trend of decreasing period with increasing temperature, and (f) they show a trend of decreasing amplitude with decreasing period. However, they possibly differ in that the decreasing trend of period with temperature may be slightly offset from that of the MWG. These eight are classified as PPNs. The other 14 all show evidence of variability on shorter timescales. They are likely hotter PPNsmore » or young planetary nebulae. However, in the MWG the numbers of PPNs peak in the F−G spectral types, while it appears that in the LMC they peak at a hotter B spectral type. One of the periodic ones shows a small, R Coronae Borealis type light curve drop.« less

Authors:
;  [1];  [2]; ;  [3];  [4]
  1. Department of Physics and Astronomy, Valparaiso University, Valparaiso, IN 46383 (United States)
  2. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD, 21218 (United States)
  3. N. Copernicus Astronomy Center, Rabianska 8, 87-100 Torun (Poland)
  4. Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warsaw (Poland)
Publication Date:
OSTI Identifier:
22522396
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 805; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AMPLITUDES; CARBON; DIAGRAMS; GRAVITATIONAL LENSES; MAGELLANIC CLOUDS; MILKY WAY; OSCILLATIONS; PERIODICITY; PHOTOMETRY; PLANETARY NEBULAE; PROTOPLANETS; SPACE; STAR EVOLUTION; STARS; VISIBLE RADIATION

Citation Formats

Hrivnak, Bruce J., Lu, Wenxian, Volk, Kevin, Szczerba, Ryszard, Hajduk, Marcin, and Soszyński, Igor, E-mail: bruce.hrivnak@valpo.edu, E-mail: wen.lu@valpo.edu. VARIABILITY IN PROTO-PLANETARY NEBULAE. III. LIGHT CURVE STUDIES OF MAGELLANIC CLOUD CARBON-RICH OBJECTS. United States: N. p., 2015. Web. doi:10.1088/0004-637X/805/1/78.
Hrivnak, Bruce J., Lu, Wenxian, Volk, Kevin, Szczerba, Ryszard, Hajduk, Marcin, & Soszyński, Igor, E-mail: bruce.hrivnak@valpo.edu, E-mail: wen.lu@valpo.edu. VARIABILITY IN PROTO-PLANETARY NEBULAE. III. LIGHT CURVE STUDIES OF MAGELLANIC CLOUD CARBON-RICH OBJECTS. United States. doi:10.1088/0004-637X/805/1/78.
Hrivnak, Bruce J., Lu, Wenxian, Volk, Kevin, Szczerba, Ryszard, Hajduk, Marcin, and Soszyński, Igor, E-mail: bruce.hrivnak@valpo.edu, E-mail: wen.lu@valpo.edu. Wed . "VARIABILITY IN PROTO-PLANETARY NEBULAE. III. LIGHT CURVE STUDIES OF MAGELLANIC CLOUD CARBON-RICH OBJECTS". United States. doi:10.1088/0004-637X/805/1/78.
@article{osti_22522396,
title = {VARIABILITY IN PROTO-PLANETARY NEBULAE. III. LIGHT CURVE STUDIES OF MAGELLANIC CLOUD CARBON-RICH OBJECTS},
author = {Hrivnak, Bruce J. and Lu, Wenxian and Volk, Kevin and Szczerba, Ryszard and Hajduk, Marcin and Soszyński, Igor, E-mail: bruce.hrivnak@valpo.edu, E-mail: wen.lu@valpo.edu},
abstractNote = {We have investigated the light variability in a sample of 22 carbon-rich post-AGB stars in the LMC and SMC, based primarily on photometric data from the Optical Gravitational Lensing Experiment survey. All are found to vary. Dominant periods are found in eight of them; these periods range from 49 to 157 days, and most of these stars have F spectral types. These eight are found to be similar to the Milky Way Galaxy (MWG) carbon-rich proto-planetary nebulae (PPNs) in several ways: (a) they are in the same period range of ∼38 to ∼160 days, (b) they have similar spectral types, (c) they are (all but one) redder when fainter, (d) they have multiple periods, closely spaced in time, with an average ratio of secondary to primary period of ∼1.0, and as an ensemble, (e) they show a trend of decreasing period with increasing temperature, and (f) they show a trend of decreasing amplitude with decreasing period. However, they possibly differ in that the decreasing trend of period with temperature may be slightly offset from that of the MWG. These eight are classified as PPNs. The other 14 all show evidence of variability on shorter timescales. They are likely hotter PPNs or young planetary nebulae. However, in the MWG the numbers of PPNs peak in the F−G spectral types, while it appears that in the LMC they peak at a hotter B spectral type. One of the periodic ones shows a small, R Coronae Borealis type light curve drop.},
doi = {10.1088/0004-637X/805/1/78},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 805,
place = {United States},
year = {2015},
month = {5}
}