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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"

608 results found.

  1. LIGO/Virgo S190901ap: Upper limits from Fermi-GBM Observations
  2. LIGO/Virgo S190901ap: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  3. LIGO/Virgo S190828j: No counterpart candidates in KAIT observations
  4. Integral GRB190828.78 Global MASTER-Net observations report
  5. LIGO/Virgo S190814bv: No candidates found in J-GEM follow-up observations
  6. LIGO/Virgo S190728q: Coverage and upper limits from MAXI/GSC observations
  7. LIGO/Virgo S190718y: No counterpart candidates in CNEOST
  8. Fermi trigger No 585007213 Global MASTER-Net observations report
  9. Fermi trigger No 584264100 Global MASTER-Net observations report
  10. LIGO/Virgo S190706ai: No counterpart candidates in KAIT observations
  11. Swift GRB190631. Global MASTER-Net observations report
  12. LIGO/Virgo S190521r: CNEOST follow-up observations
  13. Fermi GRB190520.6 Global MASTER-Net observations report
  14. LIGO/Virgo S190517h: CALET Observations
  15. LIGO/Virgo S190517h: INTEGRAL prompt observation
  16. LIGO/Virgo S190517h: INTEGRAL/SPI-ACS prompt observation
  17. LIGO/Virgo S190510g: J-GEM optical/NIR follow-up observations
  18. LIGO/Virgo S190412m: Further J-GEM optical/NIR observations
  19. GRB 190427A, Swift-BAT refined analysis
  20. LIGO/Virgo S190426c: CNEOST Optical Observations
  21. LIGO/Virgo S190425z: CNEOST Optical Observations
  22. LIGO/Virgo S190426c: SAO optical observation
  23. Fermi GRB190415.17 Global MASTER-Net observations report
  24. MAGIC follow-up of the X-ray flares of LS I +61�303 dete
  25. Swift detection of LS I +61 303
  26. Trigger 888312: Swift detection of 4U 1901+03
  27. GRB 190203A: MASTER OT detection
  28. Konus-Wind observation of GRB 190114C
  29. SWIFT GRB190106.57 Global MASTER-Net OT detection
  30. GRB 181027A: Fermi GBM detection
  31. GRB 181020A: Swift-XRT refined Analysis
  32. GRB 181010A: REM optical and NIR afterglow detection
  33. Konus-Wind observation of GRB 180828A
  34. GRB 180728B: MASTER optical observations short GRB IPN error box
  35. GRB 180728B: Fermi GBM detection
  36. GRB 180728A: MASTER OT (= new object) detection
  37. GRB 180722A: MASTER second inspection
  38. GRB 180720B: MASTER Global Net OT observations
  39. FRB 180714: MASTER optical inspection of the Fast Rado Burst Transient
  40. GRB 180718A: Fermi GBM detection
  41. Konus-Wind observation of GRB 180623A
  42. GRB 180623A: Swift detection of a burst
  43. GRB 180618A: MASTER OT observation (a short GRB with extended emission)
  44. GRB 180605A: Fermi GBM observation
  45. Konus-Wind observation of GRB 180523A
  46. Swift trigger 831888: misidentification of 4U 1416-62
  47. GRB 180504A: Swift-BAT refined analysis
  48. Konus-Wind observation of GRB 180427A
  49. Konus-Wind observation of GRB 180316A
  50. GRB 180325A: Swift-XRT refined Analysis
  51. GRB 180224A: Swift/UVOT Detection
  52. Konus-Wind observation of GRB 180111A
  53. GRB 180113A: Swift-BAT refined analysis
  54. GRB 180102A: Swift-BAT refined analysis
  55. IceCube-171106A: Konus-Wind upper limits
  56. GRB 171209A: Swift-BAT refined analysis
  57. GRB 171112A: MAXI/GSC detection
  58. IceCube-171106A: Swift Observations
  59. GRB 171027A, Swift-BAT refined analysis
  60. Swift trigger 781740: Further analysis from Swift and Fermi/GBM
  61. Numerous Fermi-GBM Subthreshold Notices are due to Swift J0243.6+6
  62. Swift Trigger 775946 is a Galactic transient, not GRB 171003
  63. GRB 171003A: LT early optical observations
  64. GRB 170903A: Swift-BAT refined analysis
  65. Konus-Wind observation of GRB 170822A
  66. LIGO/Virgo G298048: ATCA observations of candidate host galaxies
  67. Konus-Wind observation of GRB 170728B
  68. GRB 170714A, Swift-BAT refined analysis
  69. Fermi GBM Detection of possible burst from AXP 4U 0142+61
  70. GRB 170710B: Fermi GBM observation
  71. Konus-Wind observation of GRB 170705A
  72. LIGO/Virgo G268556: optical observations and classification of Pan-STARRS1 transients
  73. GRB 170524A: Swift-BAT refined analysis
  74. Swift trigger 748858: Swift BAT, XRT, and UVOT refined analysis
  75. GRB 170405A: Swift detection of a burst with an optical counterpart
  76. LIGO/Virgo G270580: optical observations and classification of PS and MASTER sources
  77. LIGO/Virgo G275697: Updated localization from LIGO data
  78. LIGO/Virgo G275697: Swift-XRT sources
  79. Konus-Wind observation of GRB 170206A
  80. LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
  81. LIGO/Virgo G268556: Pan-STARRS1 observations and summary of transient sources
  82. LIGO/Virgo G268556: GWAC_F60B (60cm) follow-up two events of EWE001 and EWE002
  83. LIGO/Virgo G268556/GW170104: Asiago Observations
  84. LIGO/Virgo G268556: ATLAS17aeu - an unusual transient within the skymap
  85. GRB 161220A: Swift-BAT refined analysis
  86. GRB 161214A: fading optical afterglow candidate with the LT
  87. Konus-Wind observation of GRB 161202A
  88. GRB 161113A: Swift/UVOT Upper Limits
  89. GRB 161109A: Swift-XRT observations
  90. Swift Trigger 718766 is not an astrophysical event.
  91. Konus-Wind observation of GRB 161020B
  92. GRB 161004A: Swift-BAT refined analysis
  93. GRB 160927A: Swift-BAT refined analysis
  94. GRB 160821B: Fermi GBM Detection
  95. Swift Trigger 707545 is likely 4U 1850-03/GS1843-02
  96. IPN Triangulation of GRB 160720A
  97. GRB 160625B CALET Gamma-Ray Burst Monitor detection
  98. Konus-Wind observation of GRB 160625B
  99. Konus-Wind observation of GRB 160530A
  100. Konus-Wind observation of GRB 160521B

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