scholarly journals Calibration En Magnitudes Absolues De La Classification BCD. Application à La Détermination Du Module De Distance Du Grand Nuage De Magellan

1973 ◽  
Vol 54 ◽  
pp. 78-85
Author(s):  
L. Divan
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Distance Modulus ◽  
Rr Lyrae ◽  
A Value ◽  
Cepheid Variables ◽  
Absolute Magnitudes

The calibration of the BCD stellar classification in absolute magnitudes (classification in three parameters λ1, D, Φb) was used to determine the distance modulus of the Large Magellanic Cloud. The described method makes use of the spectrophotometric parameters of B and A supergiants of the Large Cloud and gives a value of the distance modulus which is independent from other determinations, in particular from those which are based on the RR Lyrae and the Cepheid variables. The value found for the distance is slightly smaller than those generally admitted. The results are still based only on a limited number of measurements and new observations are in process; however, it seems doubtful that one will obtain much larger values. In other respects, the observations have shown that the parameter λ1 was still sensitive to luminosity for the B and A stars brighter than M = −8 and that the calibration of the λ1D diagram in absolute magnitudes can be extended up to M = −9.

scholarly journals Standard Galactic field RR Lyrae II: a Gaia DR2 calibration of the period–Wesenheit–metallicity relation

2019 ◽  
Vol 490 (3) ◽  
pp. 4254-4270 ◽  
Author(s):  
Jillian R Neeley ◽  
Massimo Marengo ◽  
Wendy L Freedman ◽  
Barry F Madore ◽  
Rachael L Beaton ◽  
...  
Keyword(s):  
Near Infrared ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Distance Modulus ◽  
Rr Lyrae Stars ◽  
Galactic Field ◽  
Rr Lyrae ◽  
Lyrae Stars ◽  
Distance Indicators ◽  
Made In

ABSTRACT RR Lyrae stars have long been popular standard candles, but significant advances in methodology and technology have been made in recent years to increase their precision as distance indicators. We present multiwavelength (optical UBVRcIc and Gaia G, BP, RP; near-infrared JHKs; mid-infrared [3.6], [4.5]) period–luminosity–metallicity (PLZ), period–Wesenheit–metallicity (PWZ) relations, calibrated using photometry obtained from the Carnegie RR Lyrae Program and parallaxes from the Gaia second data release for 55 Galactic field RR Lyrae stars. The metallicity slope, which has long been predicted by theoretical relations, can now be measured in all passbands. The scatter in the PLZ relations is on the order of 0.2 mag, and is still dominated by uncertainties in the parallaxes. As a consistency check of our PLZ relations, we also measure the distance modulus to the globular cluster M4, the Large Magellanic Cloud and the Small Magellanic Cloud, and our results are in excellent agreement with estimates from previous studies.

scholarly journals The distance to the Large Magellanic Cloud from first overtone RR Lyrae variables

2004 ◽  
Vol 193 ◽  
pp. 180-183
Author(s):  
A.V. Muzzin ◽  
C.M. Clement ◽  
D.R. Alves ◽  
Keyword(s):  
Fourier Coefficients ◽  
Large Magellanic Cloud ◽  
Light Curves ◽  
Log P ◽  
Distance Modulus ◽  
P Values ◽  
Rr Lyrae ◽  
Visual Distance ◽  
Bona Fide ◽  
Absolute Magnitudes

AbstractFourier coefficients have been derived for the V and R light curves of 330 bona fide RR Lyrae first-overtone (RR1) pulsators in 16 MACHO fields near the bar of the LMC. We use the Fourier phase parameter ɸ31 and log P values to select a subsample of these stars which are similar to the RR1s in the Galactic globular cluster M5. Assuming that the M5-like stars in the LMC have absolute magnitudes comparable to the HB stars in M5, we use independent studies to derive their mean absolute V magnitude and compute a visual distance modulus of μLMC = 18.43 ± 0.06 (statistical) ±0.16 (systematic). By selecting stars on the basis of their light curve parameters, we are able to derive a distance modulus that does not depend on the somewhat poorly determined Mv – [Fe/H] relation for RR Lyr stars.

scholarly journals Maximum Magnitude Vs. Rate of Decline for Novae of the LMC

1990 ◽  
Vol 122 ◽  
pp. 71-72
Author(s):  
M. Capaccioli ◽  
M. Della Valle ◽  
M. D’Onofrio ◽  
L. Rosino
Keyword(s):  
Close Agreement ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Distance Modulus ◽  
Maximum Magnitude ◽  
Rr Lyrae ◽  
Rate Of Decline

AbstractWe derive the distance modulus of the Large Magellanic Cloud (LMC) by applying the new calibrated relationship between maximum magnitude and rate of decline (MMRD). The result, , is in close agreement with the most recent determinations based on RR Lyrae and Cepheids. We also discuss the properties of the MMRD of M31 and of the LMC.

The Distance to the Large Magellanic Cloud; A Critical Review

1999 ◽  
Vol 190 ◽  
pp. 542-548 ◽  
Author(s):  
Michael Feast
Keyword(s):  
Critical Review ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Distance Modulus ◽  
A Value

Five independent methods of deriving the distance modulus of the Large Magellanic Cloud are reviewed and compared. A value in the range 18.60 to 18.80 is presently preferred.

The Distance to the Large Magellanic Cloud; A Critical Review

1999 ◽  
Vol 190 ◽  
pp. 542-548 ◽  
Author(s):  
Michael Feast
Keyword(s):  
Critical Review ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Distance Modulus ◽  
A Value

Five independent methods of deriving the distance modulus of the Large Magellanic Cloud are reviewed and compared. A value in the range 18.60 to 18.80 is presently preferred.

scholarly journals The Distance to the Large Magellanic Cloud

2000 ◽  
Vol 176 ◽  
pp. 203-207
Author(s):  
Piotr Popowski
Keyword(s):  
Galactic Center ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Distance Modulus ◽  
Local Universe ◽  
Rr Lyrae Stars ◽  
Rr Lyrae ◽  
Red Clump ◽  
Lyrae Stars ◽  
Selective Extinction

AbstractI demonstrate that the two unexpected results in the local Universe: anomalous intrinsic (V – I)0 colors of RR Lyrae stars and clump giants in the Galactic center, and very short distances to Magellanic Clouds inferred from clump giants, can be at least partially resolved with a modified coefficient of selective extinction AV/E(V – I). With this modification, I find a new clump-giant distance modulus to the Large Magellanic Cloud, μLMC = 18.27 ± 0.07, which is 0.09 larger than the Udalski (1998b) result. When distance estimates from the red clump, RR Lyrae stars and the eclipsing binary HV2274 are combined, one obtains μLMC = 18.31 ± 0.04 (internal).

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

scholarly journals The MACHO Project Large Magellanic Cloud Variable Star Inventory. XI. Frequency Analysis of the Fundamental‐Mode RR Lyrae Stars

2003 ◽  
Vol 598 (1) ◽  
pp. 597-609 ◽  
Author(s):  
C. Alcock ◽  
D. R. Alves ◽  
A. Becker ◽  
D. Bennett ◽  
K. H. Cook ◽  
...  
Keyword(s):  
Frequency Analysis ◽  
Fundamental Mode ◽  
Variable Star ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Rr Lyrae Stars ◽  
Rr Lyrae ◽  
Lyrae Stars

scholarly journals Light Curves and Metal Abundances of RR Lyrae Variables in the Bar of the Large Magellanic Cloud

2000 ◽  
Vol 176 ◽  
pp. 172-175 ◽  
Author(s):  
G. Clementini ◽  
A. Bragaglia ◽  
L. Di Fabrizio ◽  
E. Carretta ◽  
R. G. Gratton
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Photometric System ◽  
Rr Lyrae Stars ◽  
Rr Lyrae ◽  
Visual Magnitude ◽  
Metal Abundance ◽  
Definition Of ◽  
Lyrae Stars

AbstractThe Large Magellanic Cloud (LMC) is widely considered a corner-stone of the astronomical distance scale. However, a difference of 0.2−0.3 mag exists in its distance as predicted by the short and long distance scales. Distances to the LMC from Population II objects are founded on the RR Lyrae variables. We have undertaken an observational campaign devoted to the definition of the average apparent luminosity, and to the study of the mass–metallicity relation for RR Lyrae stars in the bar of the LMC. These are compared with analogous quantities for cluster RR Lyrae stars. The purpose is to see whether an intrinsic difference in luminosity, possibly due to a difference in mass, might exist between field and cluster RR Lyrae stars, which could be responsible for the well-known dichotomy between short and long distance scales. Preliminary results are presented on the V and B − V light curves, the average apparent visual magnitude, and the pulsational properties of 102 RR Lyrae stars in the bar of the LMC, observed at ESO in January 1999. The photometric data are accurately tied to the Johnson photometric system. Comparison is presented with the photometry of RR Lyrae stars in the bar of the LMC obtained by the MACHO collaboration (Alcock et al. 1996). Our sample includes 9 double-mode RR Lyrae stars selected from Alcock et al. (1997) for which an estimate of the metal abundance from the ΔS method is presented.

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