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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"

631 results found.

  1. GRB 191227A: Swift-BAT refined analysis
  2. Swift Trigger 946234: further Swift analysis
  3. GRB 191221B: Swift detection of a burst and a very bright optical candidate
  4. LIGO/Virgo S191220af: Global MASTER-Net observations report
  5. Konus-Wind observation of GRB 191218A
  6. LIGO/Virgo S191216ap: Global MASTER-Net observations report
  7. LIGO/Virgo S191212q: Global MASTER-Net observations report
  8. Fermi trigger No 596808579: Global MASTER-Net observations report
  9. GRB 191106A: Swift-BAT refined analysis
  10. GRB 191031D: Swift-BAT refined analysis
  11. GRB 191031C: Swift-BAT refined analysis
  12. GRB 191031A: Swift-BAT refined analysis
  13. TESS Detection of the Optical Emission from the Possible Untriggered GRB Associated with ZTF19abvizsw
  14. Konus-Wind observation of GRB 191004B
  15. GRB 191004A: Swift-BAT refined analysis
  16. LIGO/Virgo S190930t: J-GEM follow-up observation for Swift J221951-484240
  17. LIGO/Virgo S190930s: No counterpart candidates in KAIT observations
  18. Update to the Fermi GBM Localizations
  19. LIGO/Virgo S190910h: Identification of a GW compact binary merger candidate
  20. LIGO/Virgo S190901ap: No counterpart candidates in KAIT observations
  21. LIGO/Virgo S190901ap : GRAWITA photometric observation of candidate ZTFabvizsw and GCN 25618 revision
  22. LIGO/Virgo S190901ap: Upper limits from CALET observations.
  23. LIGO/Virgo S190901ap: Upper limits from Insight-HXMT/HE observations
  24. LIGO/Virgo S190901ap: Upper limits from Fermi-GBM Observations
  25. LIGO/Virgo S190901ap: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  26. LIGO/Virgo S190828j: No counterpart candidates in KAIT observations
  27. Integral GRB190828.78 Global MASTER-Net observations report
  28. LIGO/Virgo S190814bv: No candidates found in J-GEM follow-up observations
  29. LIGO/Virgo S190728q: Coverage and upper limits from MAXI/GSC observations
  30. LIGO/Virgo S190718y: No counterpart candidates in CNEOST
  31. Fermi trigger No 585007213 Global MASTER-Net observations report
  32. Fermi trigger No 584264100 Global MASTER-Net observations report
  33. LIGO/Virgo S190706ai: No counterpart candidates in KAIT observations
  34. Swift GRB190631. Global MASTER-Net observations report
  35. LIGO/Virgo S190521r: CNEOST follow-up observations
  36. Fermi GRB190520.6 Global MASTER-Net observations report
  37. LIGO/Virgo S190517h: CALET Observations
  38. LIGO/Virgo S190517h: INTEGRAL prompt observation
  39. LIGO/Virgo S190517h: INTEGRAL/SPI-ACS prompt observation
  40. LIGO/Virgo S190510g: J-GEM optical/NIR follow-up observations
  41. LIGO/Virgo S190412m: Further J-GEM optical/NIR observations
  42. GRB 190427A, Swift-BAT refined analysis
  43. LIGO/Virgo S190426c: CNEOST Optical Observations
  44. LIGO/Virgo S190425z: CNEOST Optical Observations
  45. LIGO/Virgo S190426c: SAO optical observation
  46. Fermi GRB190415.17 Global MASTER-Net observations report
  47. MAGIC follow-up of the X-ray flares of LS I +61�303 dete
  48. Swift detection of LS I +61 303
  49. Trigger 888312: Swift detection of 4U 1901+03
  50. GRB 190203A: MASTER OT detection
  51. Konus-Wind observation of GRB 190114C
  52. SWIFT GRB190106.57 Global MASTER-Net OT detection
  53. GRB 181027A: Fermi GBM detection
  54. GRB 181020A: Swift-XRT refined Analysis
  55. GRB 181010A: REM optical and NIR afterglow detection
  56. Konus-Wind observation of GRB 180828A
  57. GRB 180728B: MASTER optical observations short GRB IPN error box
  58. GRB 180728B: Fermi GBM detection
  59. GRB 180728A: MASTER OT (= new object) detection
  60. GRB 180722A: MASTER second inspection
  61. GRB 180720B: MASTER Global Net OT observations
  62. FRB 180714: MASTER optical inspection of the Fast Rado Burst Transient
  63. GRB 180718A: Fermi GBM detection
  64. Konus-Wind observation of GRB 180623A
  65. GRB 180623A: Swift detection of a burst
  66. GRB 180618A: MASTER OT observation (a short GRB with extended emission)
  67. GRB 180605A: Fermi GBM observation
  68. Konus-Wind observation of GRB 180523A
  69. Swift trigger 831888: misidentification of 4U 1416-62
  70. GRB 180504A: Swift-BAT refined analysis
  71. Konus-Wind observation of GRB 180427A
  72. Konus-Wind observation of GRB 180316A
  73. GRB 180325A: Swift-XRT refined Analysis
  74. GRB 180224A: Swift/UVOT Detection
  75. Konus-Wind observation of GRB 180111A
  76. GRB 180113A: Swift-BAT refined analysis
  77. GRB 180102A: Swift-BAT refined analysis
  78. IceCube-171106A: Konus-Wind upper limits
  79. GRB 171209A: Swift-BAT refined analysis
  80. GRB 171112A: MAXI/GSC detection
  81. IceCube-171106A: Swift Observations
  82. GRB 171027A, Swift-BAT refined analysis
  83. Swift trigger 781740: Further analysis from Swift and Fermi/GBM
  84. Numerous Fermi-GBM Subthreshold Notices are due to Swift J0243.6+6
  85. Swift Trigger 775946 is a Galactic transient, not GRB 171003
  86. GRB 171003A: LT early optical observations
  87. GRB 170903A: Swift-BAT refined analysis
  88. Konus-Wind observation of GRB 170822A
  89. LIGO/Virgo G298048: ATCA observations of candidate host galaxies
  90. Konus-Wind observation of GRB 170728B
  91. GRB 170714A, Swift-BAT refined analysis
  92. Fermi GBM Detection of possible burst from AXP 4U 0142+61
  93. GRB 170710B: Fermi GBM observation
  94. Konus-Wind observation of GRB 170705A
  95. LIGO/Virgo G268556: optical observations and classification of Pan-STARRS1 transients
  96. GRB 170524A: Swift-BAT refined analysis
  97. Swift trigger 748858: Swift BAT, XRT, and UVOT refined analysis
  98. GRB 170405A: Swift detection of a burst with an optical counterpart
  99. LIGO/Virgo G270580: optical observations and classification of PS and MASTER sources
  100. LIGO/Virgo G275697: Updated localization from LIGO data

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