Cassiopeia A ( Cassiopeia A ) - supernova remnant in the constellation Cassiopeia. The brightest radio source in the sky at frequencies above 1 GHz outside the solar system and one of the first discrete open radio sources.
| Cassiopeia A | |
|---|---|
 Photo of Cassiopeia A in the optical range (Hubble telescope) | |
| Observational data ( Age J2000.0 ) | |
| Supernova type | IIb [1] |
| Residue type | shell |
| Galaxy | Milky Way |
| Constellation | Cassiopeia |
| Right ascension | |
| Declination | |
| Galactic coordinates | l = 111.7 °, b = -2.1 ° |
| opening date | 1947 |
| Maximum Shine (V) | 6? |
| Distance | 11,000 St. years [2] |
| physical characteristics | |
| Ancestor | Unknown |
| Ancestor class | Unknown |
| Color Index (BV) | Unknown |
| The properties | The brightest radio source outside the solar system at frequencies above 1 GHz |
| Other designations | |
| Cas A; 3C 461; 4C +58.40; 8C 2321 + 585 | |
A supernova erupted in about 11 thousand light-years in our galaxy . [2] [3] The expanding substance of the residue currently has a size of about 10 light-years from the point of view of the earth observer.
It is believed that a supernova explosion could have been observed from the Earth 300 years ago, but there are no historical references to the “guest-star” or the supernatural progenitor, despite the fact that Cassiopeia A is located in the circumpolar constellation, which is observed in the middle latitudes of the Northern Hemisphere all year round. It is possible that in the optical range, supernova radiation was attenuated by interstellar dust . There is a hypothesis that the English astronomer John Flemstead saw a supernova and cataloged it as a 6th magnitude star 3 of Cassiopeia on August 16, 1680. [4] It is assumed that the exploding star was unusually massive, and by the time of the explosion it had already dropped a significant amount of its substance into outer space. The substance enveloped the star, effectively absorbing the radiation from the star’s flare.
According to another hypothesis from a recent interdisciplinary study, this supernova was a “midday star” observed in 1630 and seen as a harbinger of the birth of King Charles II of England. [5] No other supernova in the Milky Way has since been observed from the Earth with the naked eye.
Cassiopeia A is designated 3C 461 in the Third Cambridge Radio Source Directory and G111.7-2.1 in the Green Catalog of Supernova Remnants .
In 1937, the first radio telescope was built with a parabolic mirror by Groot Reber , an amateur radio operator from Whitton ( USA , Illinois ). The radio telescope was located in the backyard of Groot's parents' house, had a parabolic shape and an antenna diameter of about 9 meters. With the help of a tool, Groot constructed a sky map in the radio range, on which the central regions of the Milky Way and the bright radio sources Cygnus A ( Cyg A ) and Cassiopeia A ( Cas A ) are clearly visible. [6]
Cassiopeia A was discovered by the English radio astronomers Ryle and Smith in 1948. [7] In the optical range, Cassiopeia A was discovered in 1951 by Baade and Minkowski. [8] According to other sources, it was discovered in 1950. [9]
According to the Spitzer space telescope , a neutron star was formed as a result of a supernova explosion [10] , possibly of the magnetar class [11] .
Content
- 1 Radio brightness
- 2 Shell expansion
- 3 X-ray radiation
- 4 Supernova Reflected Echo
- 5 phosphorus detection
- 6 Location and conditions of observation
- 7 Images
- 8 See also
- 9 notes
- 10 Links
- 10.1 in databases
Radio brightness
The radiation flux density is 2720 Jy at a frequency of 1 GHz in 1980. [12] As the supernova remnants cool, the radiation flux density decreases. At a frequency of 1 GHz, this decrease is about 0.97 ± 0.04 percent per year. [12] At present, at frequencies below 1 GHz, the radiation of Cassiopeia A is less intense than that of the Swan A radio galaxy.
Shell Extension
The supernova shell had a temperature of about 30 million degrees Kelvin and expanded at a speed of 4-6 thousand kilometers per second. [2]
It was previously assumed that supernova remnants expand evenly. But observations using the Hubble telescope showed that there are streams with higher speeds of 5.5-14.5 km / s, with the highest speeds being achieved in two practically opposite jets. [2] In photographs where various chemical compounds are colored with colors, it can be seen that similar substances often remain nearby with the expansion of supernova remnants. [3]
X-ray
In 1999, using the Chandra space X-ray laboratory, a “hot point source ” was discovered near the center of the nebula, which is a neutron star remaining after a supernova explosion. [13]
Cas X-1 (or Cas XR-1), an X-ray source in the constellation Cassiopeia , was not detected during the flight of the American meteorological rocket Aerobee on June 16, 1964, although it was supposed that there could be such a source. [14] On October 1, 1964, a new Cas A scan was performed using another Aerobee rocket, but it was not possible to detect a significant x-ray flux from this point. [15] On April 25, 1965, the Aerobee rocket managed to detect Cas XR-1, [16] the coordinates of RA 23 h 21 m Dec + 58 ° 30 ′ [17] Cas X-1 is Cas A (Cassiopeia A), Type II SNR with RA coordinates 23 h 18 m Dec + 58 ° 30 ′ [18] Designations Cassiopeia X-1, Cas XR-1, Cas X-1 are no longer used, X-ray source is Cassiopeia A ( supernova remnant G111.7-02.1 ), 2U 2321 + 58.
Supernova Reflected Echo
The infrared echo from the explosion of Cassiopeia A was observed on nearby gas clouds using the Spitzer space telescope. [19] The recorded spectrum became evidence that this supernova was of type IIb , ie the explosion occurred as a result of the internal collapse of a massive star , most likely a red supergiant with a helium core, which lost almost its entire hydrogen shell. This was the first observation of the infrared echo from a supernova explosion, which itself was not directly observed, which opens up the opportunity to study and reconstruct astronomical events from the past. [twenty]
Phosphorus Detection
In 2013, astronomers managed to detect phosphorus in Cassiopeia A, which confirms the formation of this element in supernovae using nucleosynthesis . The ratio of phosphorus to iron in the supernova remnant could be up to 100 times higher than the average in the Milky Way. [21]
Location and observation conditions
Although Cassiopeia A is clearly visible in the radio range, its radiation is relatively weak in the optical range. It can be seen in photographs with a long exposure or using an amateur telescope from 234 mm with filters. [22]
Images
Gal. Longitude 111.735 °
Gal. −2.130 °
Distance 11,000 St. years
See also
- List of supernova remnants
- Light echo
- History of Radio Astronomy
Notes
- ↑ Scientists Hold Séance for Supernova (inaccessible link - history ) . Date of treatment May 29, 2008.
- ↑ 1 2 3 4 Fesen, Robert A .; Hammell, Molly C .; Morse, Jon & Chevalier, Roger A. (July 2006), " The Expansion Asymmetry and Age of the Cassiopeia A Supernova Remnant ", The Astrophysical Journal T. 645 (1): 283–292, doi : 10.1086 / 504254 , < http : //adsabs.harvard.edu/abs/2006ApJ ... 645..283F >
- ↑ 1 2 Stover, Dawn (2006), "Life In A Bubble", Popular Science T. 269 (6)
- ↑ Hughes DW Did Flamsteed see the Cassiopeia A supernova? (Eng.) // Nature . - 1980. - Vol. 285 , no. 5761 . - P. 132-133 . - DOI : 10.1038 / 285132a0 .
- ↑ Oullette, Jennifer Did Supernova Herald the Birth of a King? . Discovery.com. Date of treatment April 18, 2011.
- ↑ Kip Thorne . Black holes and folds of time. - M .: Publishing house of physical and mathematical literature, 2007. - S. 323—325. - 616 p. - ISBN 9785-94052-144-4 .
- ↑ Ryle, M. ; Smith, FG . A New Intense Source of Radio-Frequency Radiation in the Constellation of Cassiopeia // Nature : journal. - 1948. - 18 September ( vol. 162 , no. 4116 ). - P. 462-463 . - DOI : 10.1038 / 162462a0 . - .
- ↑ I.S. Shklovsky. Stars: their birth, life and death. - 3rd ed .. - M .: Nauka, 1984. - S. 220,221. - 384 p.
- ↑ Fabian, AC Astronomy. A blast from the past (Eng.) // Science. - 2008 .-- Vol. 320 , no. 5880 . - P. 1167-1168 . - DOI : 10.1126 / science.1158538 . - PMID 18511676 .
- ↑ How the Universe was expanding in 2009, Sergey Popov, Maxim Borisov “Trinity Option” No. 01 (45), January 19, 2010
- ↑ Cassiopeia A is in no hurry to die
- ↑ 1 2 Baars, JWM; Genzel, R .; Pauliny-Toth, IIK; Witzel, A. The Absolute Spectrum of Cas A; An Accurate Flux Density Scale and a Set of Secondary Calibrators (Eng.) // Astronomy and Astrophysics : journal. - EDP Sciences 1977. - Vol. 61 . - P. 99 . - .
- ↑ Elshamouty, KG; Heinke, CO; Sivakoff, GR; Ho, WCG; Shternin, PS; Yakovlev, DG; Patnaude, DJ; David, L. Measuring the cooling of the neutron star in Cassiopeia A with all Chandra X-Ray Observatory detectors (Eng.) // The Astrophysical Journal : journal. - IOP Publishing 2013. - Vol. 777 , no. 1 . - P. 22 . - DOI : 10.1088 / 0004-637X / 777/1/22 . - . - arXiv : 1306.3387 .
- ↑ Observational results of X-ray astronomy // Astronomical Observations from Space Vehicles, Proceedings from Symposium No. 23 Held in Liege, Belgium, 17 to 20 August 1964 / Steinberg JL. - International Astronomical Union , 1965. - P. 227–39.
- ↑ Fisher PC, Johnson HM, Jordan WC, Meyerott AJ, Acton LW Observations of Cosmic X-rays (Eng.) // The Astrophysical Journal . - IOP Publishing , 1966. - Vol. 143 . - P. 203-217 . - DOI : 10.1086 / 148491 . - .
- ↑ Byram ET, Chubb TA, Friedman H. Cosmic X-ray Sources, Galactic and Extragalactic (English) // Science . - 1966 .-- April ( vol. 152 , no. 3718 ). - P. 66-71 . - DOI : 10.1126 / science.152.3718.66 . - . - PMID 17830233 .
- ↑ Friedman H., Byram ET, Chubb TA Distribution and Variability of Cosmic X-Ray Sources (English) // Science : journal. - 1967. - April ( vol. 156 , no. 3773 ). - P. 374-378 . - DOI : 10.1126 / science.156.3773.374 . - . - PMID 17812381 .
- ↑ Webber WR X-ray astronomy-1968 vintage (unknown) // Proc Astron Soc Australia. - 1968. - December ( t. 1 ). - S. 160-164 . - .
- ↑ Krause, Oliver; Birkmann; Usuda; Hattori; Goto; Rieke Misselt. The Cassiopeia A Supernova was of Type IIb (English) // Science . - 2008 .-- Vol. 320 , no. 5880 . - P. 1195-1197 . - DOI : 10.1126 / science.1155788 . - . - arXiv : 0805.4557 . - PMID 18511684 .
- ↑ Fabian, Andrew C. A Blast from the Past (Eng.) // Science . - 2008 .-- Vol. 320 , no. 5880 . - P. 1167-1168 . - DOI : 10.1126 / science.1158538 . - PMID 18511676 .
- ↑ Koo, B. -C .; Lee, Y. -H .; Moon, D. -S .; Yoon, S. -C .; Raymond, JC Phosphorus in the Young Supernova Remnant Cassiopeia A (Eng.) // Science: journal. - 2013 .-- Vol. 342 , no. 6164 . - P. 1346-1348 . - DOI : 10.1126 / science.1243823 . - . - arXiv : 1312.3807 . - PMID 24337291 .
- ↑ Howard Banich. A Visual Guide to the Cassiopeia A Supernova Remnant. Sky & Telescope, December 2014.
- ↑ Reber G. Cosmic Static . - Astrophys. J., November, 1944 .-- T. 100 . - S. 279-287 . (Retrieved June 14, 2011)
- ↑ Kip Thorne . Black holes and folds of time. - M .: Publishing house of physical and mathematical literature, 2007. - S. 323—325. - 616 p. - ISBN 9785-94052-144-4 .