Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

21101 results found.

  1. LIGO/Virgo S190728q: Optical Counterpart Candidates from DECam-GROWTH
  2. LIGO/Virgo S190728q: No transient candidates in CALET observations
  3. LIGO/Virgo S190728q: No counterpart candidates in KAIT observations
  4. LIGO/Virgo S190728q: ZTF19abjethn TShAO and NUTTelA-TAO optical observations / classification
  5. LIGO/Virgo S190728q: Update on Sky-Localization and Source-Classification
  6. LIGO/Virgo S190728q: Pan-STARRS detection of the transient AT2019lvs/ZTF19abjethn 18hrs before S190728q
  7. LIGO/Virgo S190728q: No counterpart candidates in the Swift/BAT Observations
  8. LIGO/Virgo S190728q: Optical Candidate from the Zwicky Transient Facility ZTF19abjethn
  9. LIGO/Virgo S190728q: No counterpart candidates in Fermi-LAT observations
  10. LIGO/Virgo S190728q: Upper limits from Fermi-GBM Observations
  11. LIGO/Virgo S190728q: no counterpart candidates in AGILE-GRID observations
  12. LIGO/Virgo S190728q: No counterpart candidates in AGILE-MCAL observations
  13. LIGO/Virgo S190728q: No counterpart candidates in HAWC observations
  14. LIGO/Virgo S190728q: Coverage and upper limits from MAXI/GSC observations
  15. LIGO/Virgo S190727h: No transient candidates in CALET observations
  16. LIGO/Virgo S190728q Global MASTER-Net observations report
  17. Fermi trigger No 585988241 Global MASTER-Net observations report
  18. GRB 190727B: Fermi GBM observations
  19. LIGO/Virgo S190727h: No counterpart candidates in KAIT observations
  20. LIGO/Virgo S190727h: No counterpart candidates in the Swift/BAT Observations
  21. LIGO/Virgo S190727h: No counterpart candidates in Fermi-LAT observations
  22. LIGO/Virgo S190727h: Upper limits from Fermi-GBM Observations
  23. LIGO/Virgo S190727h: No counterpart candidates in HAWC observations
  24. LIGO/Virgo S190727h: No counterpart candidates in AGILE-MCAL observations
  25. LIGO/Virgo S190727h: Coverage and upper limits from MAXI/GSC observations
  26. LIGO/Virgo S190727h Global MASTER-Net observations report
  27. Fermi trigger No 585864875 Global MASTER-Net observations report
  28. Fermi trigger No 585847498 Global MASTER-Net observations report
  29. Fermi trigger No 585856427 Global MASTER-Net observations report
  30. LIGO/Virgo S190718y: Swift XRT observations, 45 X-ray sources
  31. LIGO/Virgo S190720a: Thacher Observatory follow-up observations
  32. Fermi trigger No 585621841 Global MASTER-Net observations report
  33. Fermi trigger No 585559462 Global MASTER-Net observations report
  34. LIGO/Virgo S190720a: No counterpart candidates in CNEOST observations
  35. LIGO/Virgo S190720a: No counterpart candidates in Fermi-LAT observations
  36. LIGO/Virgo S190720a: Upper limits from CALET observations
  37. LIGO/Virgo S190720a: No counterpart candidates in KAIT observations
  38. GRB 190719C: Swift/UVOT Upper Limits
  39. LIGO/Virgo S190720a: No counterpart candidates in the Swift/BAT Observations
  40. LIGO/Virgo S190720a: Upper limits from Fermi-GBM Observations
  41. LIGO/Virgo S190720a: Upper limits from AGILE-GRID observations
  42. LIGO/Virgo S190720a: Coverage and upper limits from MAXI/GSC observations
  43. LIGO/Virgo S190718y: No counterpart candidates in CNEOST
  44. LIGO/Virgo S190720a: AGILE-MCAL observations
  45. LIGO/Virgo S190720a Global MASTER-Net observations report
  46. LIGO/Virgo S190720a: No counterpart candidates in HAWC observations
  47. Fermi trigger No 585196946 Global MASTER-Net observations report
  48. GRB 190719C: NOT candidate optical afterglow and host
  49. LIGO/Virgo S190718y: No counterpart candidates in KAIT observations
  50. LIGO/Virgo S190718y: Upper limits from Insight-HXMT/HE observations
  51. LIGO/Virgo S190718y: No counterpart candidates in Fermi-LAT observations
  52. LIGO/Virgo S190718y: Coverage and upper limits from MAXI/GSC observations
  53. LIGO/Virgo S190718y: Upper limits from CALET observations
  54. LIGO/Virgo S190718y: No counterpart candidates in the Swift/BAT Observations
  55. LIGO/Virgo S190718y: Upper limits from Fermi-GBM Observations
  56. GRB 190718A: Swift/UVOT Upper Limits
  57. LIGO/Virgo S190718y Global MASTER-Net observations report
  58. Swift GRB190718.2 Global MASTER-Net observations report
  59. Fermi trigger No 585007213 Global MASTER-Net observations report
  60. Fermi trigger No 584977168 Global MASTER-Net observations report
  61. GRB 190714A: an X-ray flare from 2E 1624.6+1504/UCAC4 525-061488
  62. Fermi trigger No 584929684 Global MASTER-Net observations report
  63. Fermi trigger No 584929684 Global MASTER-Net observations report
  64. GRB 190708B: confirmation of the X-ray afterglow
  65. Fermi trigger No 584804684 Global MASTER-Net observations report
  66. GRB 190714A: Tiled Swift observations
  67. Fermi trigger No 584710308 Global MASTER-Net observations report
  68. IceCube-190712A : Upper limits from Insight-HXMT/HE observations
  69. Fermi-LAT Gamma-ray Observations of IceCube-190712A
  70. Fermi trigger No 584637077 Global MASTER-Net observations report
  71. IceCube-190712A: Upper limits from Fermi-GBM Observations
  72. IceCube Alert 190712.05 Global MASTER-Net observations report
  73. Fermi trigger No 584590606 Global MASTER-Net observations report
  74. Fermi trigger No 584583925 Global MASTER-Net observations report
  75. GRB 190708B: Swift-XRT observations
  76. LIGO/Virgo S190706ai: Upper limits from Insight-HXMT/HE observations
  77. Fermi trigger No 584465880 Global MASTER-Net observations report
  78. Fermi trigger No 584404689 Global MASTER-Net observations report
  79. LIGO/Virgo S190707q: MASTER OT seach result
  80. LIGO/Virgo S190707q: No counterpart candidates in the CNEOST
  81. LIGO/Virgo S190707q: No counterpart candidates in the Swift/BAT Observations
  82. GRB 190708B: Tiled Swift observations
  83. MAXI GRB190708.83 Global MASTER-Net observations report
  84. Fermi trigger No 584264100 Global MASTER-Net observations report
  85. LIGO/Virgo S190707q: Upper limits from CALET observations
  86. LIGO/Virgo S190707q: No counterpart candidates in Fermi-LAT observations
  87. LIGO/Virgo S190707q: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observations
  88. LIGO/Virgo S190706ai: No counterpart candidates in KAIT observations
  89. LIGO/Virgo S190706ai: No transient candidates from CALET observations
  90. LIGO/Virgo S190707q: Upper limits from Fermi-GBM Observations
  91. LIGO/Virgo S190706ai: No counterpart candidates in the Swift/BAT Observations
  92. GRB 190706B: Swift/UVOT Detection
  93. LIGO/Virgo S190707q Global MASTER-Net observations report
  94. LIGO/Virgo S190706ai: No counterpart candidates in Fermi-LAT observations
  95. LIGO/Virgo S190701ah: No counterpart candidates in Fermi-LAT observations
  96. LIGO/Virgo S190707q: Upper limits from AGILE-GRID observations
  97. LIGO/Virgo S190707q: No counterpart candidates in AGILE-MCAL observations
  98. LIGO/Virgo S190707q: No counterpart candidates in HAWC observations
  99. LIGO/Virgo S190706ai: Upper limits from Fermi-GBM Observations
  100. LIGO/Virgo S190701ah: GRAWITA VST-ESO PARANAL observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov