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MY'STORY

The MOVE Fire

This is a personal recollection on the Move fire on May 13, 1985 Philadelphia police fired thousands of rounds at the MOVE house, city officials approved dropping an explosive device on the roof, the resulting fire was allowed to burn, 11 people—including five children—died, and 61 homes were destroyed. Philadelphia City Council later called it a “brutal attack carried out by the City of Philadelphia on its own citizens” and acknowledged that no individual faced criminal consequences for the bombing. One timeline correction worth preserving for the BHP record: the major previous MOVE-police confrontation was August 8, 1978, about seven years before the bombing, not a year or two earlier. Officer James Ramp was killed, other police and firefighters were wounded, nine MOVE members were later convicted, and television cameras recorded police beating Delbert Africa during his arrest. The 1985 MOVE Commission later specifically criticized city planners for failing to adequately use lessons from that 1978 confrontation. And that actually strengthens the point you’re making: 1985 did not happen without precedent or institutional memory. There had already been a deadly confrontation with MOVE, years of conflict, negotiations and police involvement before Osage Avenue.

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BLACK FACTS
The Truths They Never Taught You...

Ruler of the Mali Empire in the 14th century

Mansa Musa was the ruler of the Mali Empire in West Africa. Details recorded here should be sourced; unknown information is left blank.

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Wikipedia

HD 124448

HD 124448

A light curve for V821 Centauri, plotted from TESS data. Adapted from Jeffery et al. (2020)[1]
Observation data
Epoch J2000      Equinox ICRS
Constellation Centaurus
Right ascension 14h 14m 58.6293s[2]
Declination −46° 17′ 19.294″[2]
Apparent magnitude (V) 9.94 - 10.03[3]
Characteristics
Spectral type B(p)[4]
Variable type PV Tel?[3]
Astrometry
Proper motion (μ) RA: −6.544±0.038 mas/yr
Dec.: −0.049±0.032 mas/yr
Parallax (π)0.6240±0.0312 mas[2]
Distance5,200 ± 300 ly
(1,600 ± 80 pc)
Details
Mass6.7[5] M☉
Radius5.2[2] R☉
Luminosity1,282[2] L☉
Surface gravity (log g)3.86[5] cgs
Temperature15,481[5] K
Metallicity [Fe/H]−0.55[5] dex
Other designations
V821 Cen, HD 124448, HIP 69619, 2MASS J14145863-4617192[6]
Database references
SIMBADdata

HD 124448, also called Popper's Star and V821 Centauri, is an extreme helium star in the Centaurus constellation.[1] Discovered by astronomer Daniel Popper, this star has a spectral classification of B2-B3.[7][8]

Peter M. Corben et al. announced that the star is a variable star, in 1972.[9] It was given its variable star designation, V821 Centauri, in 1981.[10]

References

[edit]
  1. ^ a b Jeffery, C. Simon; Barentsen, Geert; Handler, Gerald (2020). "TESS photometry of extreme helium stars PV Tel and V821 Cen". Monthly Notices of the Royal Astronomical Society. 495 (1): L135–L138. arXiv:2006.00946. Bibcode:2020MNRAS.495L.135J. doi:10.1093/mnrasl/slaa075.
  2. ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  3. ^ a b "V821 Cen". General Catalog of Variable Stars. Sternberg Astronomical Institute. Retrieved 24 May 2023.
  4. ^ Houk, Nancy (1978). "Michigan catalogue of two-dimensional spectral types for the HD stars". Ann Arbor: Dept. Of Astronomy. Bibcode:1978mcts.book.....H.
  5. ^ a b c d Khalatyan, A.; Anders, F.; Chiappini, C.; Queiroz, A. B. A.; Nepal, S.; Dal Ponte, M.; Jordi, C.; Guiglion, G.; Valentini, M.; Torralba Elipe, G.; Steinmetz, M.; Pantaleoni-González, M.; Malhotra, S.; Jiménez-Arranz, Ó.; Enke, H.; Casamiquela, L.; Ardèvol, J. (2024). "Transferring spectroscopic stellar labels to 217 million Gaia DR3 XP stars with SHBoost". Astronomy and Astrophysics. 691: A98. arXiv:2407.06963. Bibcode:2024A&A...691A..98K. doi:10.1051/0004-6361/202451427.
  6. ^ "HD 124448". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved May 23, 2023.
  7. ^ Schoenberner, D.; Wolf, R. E. A. (1974). "Fine analysis of Popper's star HD 124448". Astronomy and Astrophysics. 37: 87. Bibcode:1974A&A....37...87S.
  8. ^ Popper, Daniel M. (1946). "The Spectrum of HD 124448. Second Note". Publications of the Astronomical Society of the Pacific. 58 (345): 370. Bibcode:1946PASP...58..370P. doi:10.1086/125875. S2CID 121599294.
  9. ^ Corben, P. M.; Carter, B. S.; Banfield, R. M.; Harvey, G. M. (1972). "UBV Photometry of 500 Southern Stars [erratum: 1973MNSSA..32...48C]". Monthly Notes of the Astron. Soc. Southern Africa. 31: 7–22. Bibcode:1972MNSSA..31....7C. Retrieved 16 January 2025.
  10. ^ Kholopov, P. N.; Samus, N. N.; Kukarkina, N. P.; Medvedeva, G. I.; Perova, N. B. (February 1981). "65th Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 1921: 1–21. Bibcode:1981IBVS.1921....1K. Retrieved 16 January 2025.
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Wikipedia

HD 124448

HD 124448, also called Popper's Star and V821 Centauri, is an extreme helium star in the Centaurus constellation. Discovered by astronomer Daniel Popper, this star has a spectral classification of B2-B3. Peter M. Corben et al. announced that the star is a variable star, in 1972. It was given its variable star designation, V821 Centauri, in 1981.

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Wikipedia

IRAS 13224−3809

IRAS 13224−3809 is a highly active and fluctuating Seyfert 1 galaxy in the constellation Centaurus about 1 billion light-years from Earth. The galaxy is notable due to its centrally located supermassive black hole that is closely studied by astronomers using x-ray astronomy, particularly X-ray reverberation echo mapping techniques, in an effort to better understand the inner workings, including mass and spin, of black holes.

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Wikipedia

Tau Centauri

Tau Centauri is a solitary star in the southern constellation of Centaurus. Its name is a Bayer designation that is Latinized from τ Centauri, and abbreviated Tau Cen or τ Cen. This star is visible to the naked eye with an apparent visual magnitude of +3.86. The distance to this star, based upon an annual parallax shift of 24.3 mas, is 131 light years. It makes a star system with Gamma Centauri at 98% probability, both separated by 1.7 ly (0.53 pc). This is an A-type star with stellar classifications of A0 V or A1 IVnn, indicating it may be a main sequence star or a more evolved subgiant star. It is around 132 million years old and is spinning rapidly with a projected rotational velocity of 296.8 km/s. This is giving the star an oblate shape, with an estimated equatorial girth that is 30% larger than the polar radius. The star has an estimated 2.3 times the mass of the Sun and 2.7 times the Sun's radius.

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Wikipedia

Upsilon2 Centauri

Upsilon2 Centauri is a binary star system in the southern constellation Centaurus. Its name is a Bayer designation that is Latinized from υ2 Centauri, and abbreviated Upsilon2 Cen or υ2 Cen. This system is visible to the naked eye as a point of light with a combined apparent visual magnitude of +4.33. Based upon an annual parallax shift of 2.57 mas as seen from Earth, this star is located roughly 1,300 light years from the Sun. Relative to its neighbors, the system has a peculiar velocity of 39.2+8.8−15.2 km/s and it may form a runaway star system. This is a single-lined spectroscopic binary star system with an orbital period of 207.357 days and an eccentricity of 0.55. The primary component has the spectrum of an evolved F-type giant/bright giant hybrid with a stellar classification of F7 II/III. It is around 46 million years old with 6.9 times the mass of the Sun. The star is radiating 3,919 times the Sun's luminosity from its photosphere at an effective temperature of 6,495 K.

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TOPIC OF THE DAY

Greenwood / Black Wall Street

Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.

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TRIVIA QUESTION OF THE DAY

What prosperous Tulsa district became widely known as “Black Wall Street”?

The Greenwood District.