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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

28041 results found.

  1. Update of alert from the HAWC Burst Monitor HAWC-200709A
  2. GRB 200709B/HAWC-200907A: Swift-XRT further observations
  3. HAWC-200907A: No Neutrino Counterpart detected with ANTARES
  4. GRB 200709B: Swift-XRT observations
  5. GRB 200707A: Insight-HXMT/HE detection
  6. GRB 200704A: Insight-HXMT/HE detection
  7. Fermi-LAT-ANTARES 200407a Coincidence
  8. GRB 200703B: Insight-HXMT/HE detection
  9. GRB 200703B: AstroSat CZTI detection
  10. Trigger 980513: Swift detection of SGR Swift J1818.0-1607
  11. GRB 200701A: Swift-BAT refined analysis
  12. Fermi-GBM Sub-Threshold Detection of GRB 200701A
  13. GRB 200701A: Swift detection of a burst
  14. GRB 200630A: Swift-BAT refined analysis
  15. GRB 200630A: Swift/UVOT Upper Limits
  16. GRB 200630A: Swift-XRT refined Analysis
  17. GRB 200623A: Swift XRT further observations
  18. GRB 200630A: Fermi GBM detection
  19. GRB 200629A: AstroSat CZTI detection
  20. GRB 200630A: Enhanced Swift-XRT position
  21. GRB 200630A: Swift detection of a burst
  22. GRB 200629A: BALROG localization (Fermi Trigger 615127794 / GRB 200629535)
  23. Konus-Wind detection of short/hard GRB 200623B
  24. GRB 200623A: LBT optical observations
  25. GRB 200623A : SMA observations at Swift/XRT Source #3
  26. Updated catalog of X-ray bursts of SGR J1935+2154 from Insight-HXMT observations
  27. GRB 200623A: MMT observations at XRT Source #3
  28. GRB 200623A: Swift/UVOT Upper Limits
  29. IPN triangulation of GRB 200623B (short)
  30. GRB 200623A: Swift-XRT observations
  31. GRB 200623A: OAJ deep multi-color imaging, XRT #2 is pre-detected
  32. GRB 200623A: TNG optical observations
  33. GRB 200623A: AbAO afterglow candidate within XRT #2
  34. IceCube-200620A: No significant detection in HAWC
  35. IceCube-200620A: Upper limits from a search for additional neutrino events in IceCube
  36. Fermi-LAT Gamma-ray Observations of IceCube-200620A
  37. IceCube-200620A: No ANTARES neutrino counterpart
  38. GRB 200613A: R-band observations from HCT
  39. GRB 200613A: Further Liverpool Telescope observations
  40. GRB 200619B: AstroSat CZTI detection
  41. GRB 200619A: Fermi GBM observation
  42. LIGO/Virgo MS200618aq: Retraction of a test binary neutron star candidate
  43. LIGO/Virgo MS200619bf: Retraction of a test binary neutron star candidate
  44. LIGO/Virgo MS200618bx: Retraction of a test binary neutron star candidate
  45. LIGO/Virgo MS200618bq: Retraction of a test binary neutron star candidate
  46. GRB 200619A: Insight-HXMT/HE detection
  47. GRB 200613A: SAO RAS optical observations
  48. GRB 200617A: Insight-HXMT/HE detection
  49. IceCube-200530A - SN2020lls likely unrelated
  50. Swift/UVOT Observations of IceCube 200615A
  51. LIGO/Virgo MS200614ct: Identification of a test binary black hole candidate
  52. Swift-XRT observations of IceCube 200615A
  53. IceCube-200615A: No significant detection in HAWC
  54. GRB 200613A: Jet-break from Xinglong-2.16m optical observations
  55. Fermi-LAT Gamma-ray Observations of IceCube-200615A
  56. IceCube-200614A: No significant detection in HAWC
  57. IceCube-200615A: Upper limits from a search for additional neutrino events in IceCube
  58. Fermi-LAT Gamma-ray Observations of IceCube-200614A and detection of a new gamma-ray source, Fermi J0202.8+3132
  59. LIGO/Virgo MS200615ce: Identification of a test binary black hole candidate
  60. GRB 200613A: CALET Gamma-Ray Burst Monitor detection
  61. LIGO/Virgo MS200614bz: Test Identification of a binary neutron star candidate
  62. GRB 200613A: MITSuME Akeno optical upper limits
  63. GRB 200615B: MAXI/GSC detection
  64. IceCube-200614A: Upper limits from a search for additional neutrino events in IceCube
  65. IceCube-200615A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  66. IceCube-200614A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  67. LIGO/Virgo MS200615h: Retraction of a test binary neutron star candidate
  68. GRB 200613A: Continued Xinglong-2.16m optical observations
  69. GRB 200613A: Swift/UVOT Detection
  70. GRB 200613A: Xinglong-2.16m optical observations
  71. GRB 200613A: Liverpool Telescope observations
  72. GRB 200613A: Swift-XRT afterglow detection
  73. GRB 200612A: Fermi GBM detection
  74. GRB 200613A: Fermi GBM observation
  75. GRB 200612A: Swift/UVOT Upper Limits
  76. Baksan Neutrino Observatory Alert 200611.74: Global MASTER-Net observations report
  77. BALROG localization (Fermi Trigger 613719013 / GRB 200613229)
  78. GRB 200612A: Swift-BAT refined analysis
  79. GRB 200612A: Swift-XRT refined Analysis
  80. Konus-Wind observation of ultra-long GRB 200612A
  81. GRB 200612A: Enhanced Swift-XRT position
  82. Swift GRB200612.19: Global MASTER-Net OT detection
  83. GRB 200612A: Swift detection of a burst
  84. GRB 200609A: Insight-HXMT/HE detection
  85. GRB 200608A: Swift-BAT refined analysis
  86. GRB 200608A: Swift detection of a burst
  87. GRB 200607B: AstroSat CZTI detection
  88. IPN triangulation of GRB 200605A (short)
  89. GRB 200607A: BALROG localization (Fermi Trigger 613212114 / GRB 200607362)
  90. GRB 200530A: Fermi GBM detection
  91. 1RXS J1708−4009: Swift-BAT refined analysis
  92. GRB 200604A: AstroSat CZTI detection
  93. GRB 200529A: Swift/UVOT Upper Limits
  94. Konus-Wind observation of GRB200528A
  95. GRB 200601A: Insight-HXMT/HE detection
  96. IceCube-200530A: Upper limits from a search for additional neutrino events in IceCube
  97. Fermi-LAT Gamma-ray Observations of IceCube-200530A
  98. GRB 200529A: MITSuME Akeno optical upper limits
  99. GRB 200601A: Fermi GBM Final Real-time Localization
  100. IceCube-200530A: No significant detection in HAWC

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