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"

21093 results found.

  1. Fermi trigger No 581478912 Global MASTER-Net observations report
  2. Fermi trigger No 581469752 Global MASTER-Net observations report
  3. GRB 190530A: optical follow-up observations at Konkoly
  4. GRB190604B: Swift/UVOT detection
  5. Fermi trigger No 581337762 Global MASTER-Net observations report
  6. GRB 190531B: CALET Gamma-Ray Burst Monitor detection
  7. S190602aq: MASTER OT detection
  8. LIGO/Virgo S190602aq: Upper limits from CALET observations
  9. LIGO/Virgo S190602aq: Upper limits from Insight-HXMT/HE observations
  10. Fermi trigger No 581281470 Global MASTER-Net observations report
  11. GRB 190531B: Swift/UVOT Upper Limits
  12. Konus-Wind observation of GRB 190531B
  13. GRB 190530A: R-band observation from HCT
  14. LIGO/Virgo S190602aq: upper limit in INTEGRAL SPI-ACS prompt observations
  15. LIGO/Virgo S190602aq: No counterpart candidates in Fermi-LAT observations
  16. LIGO/Virgo S190602aq: No counterpart candidates in the Swift/BAT Observations
  17. LIGO/Virgo S190602aq: Upper limits from Fermi-GBM Observations
  18. LIGO/Virgo S190602aq: Upper limits from AGILE-GRID observations
  19. LIGO/Virgo S190602aq: No counterpart candidate in AGILE-MCAL observations
  20. LIGO/Virgo S190602aq Global MASTER-Net observations report
  21. LIGO/Virgo S190602aq: Coverage and upper limits from MAXI/GSC observations
  22. LIGO/Virgo S190602aq: No counterpart candidates in HAWC observations
  23. GRB 190530A: Mondy and AbAO optical observations
  24. Fermi trigger No 581068049 Global MASTER-Net observations report
  25. GRB 190530A: Konkoly optical observations of the afterglow
  26. GRB 190530A: SAO RAS optical observations
  27. GRB 190531B: MASTER optical observation
  28. GRB 190531B: Swift-XRT afterglow detection
  29. GRB 190531B: Fermi GBM observations
  30. Fermi Fermi trigger No 581002688 Global MASTER-Net observations report
  31. GRB 190530A: Swift/UVOT Detection
  32. GRB 190531B: Swift ToO observations
  33. GRB 190530A: Steep afterglow decay found by OSN
  34. GRB 190530A: AbAO optical observations
  35. GRB 190530A: Xinglong 2.16m optical observation
  36. GRB 190530A: optical afterglow detection by 5 MASTER telescopes
  37. GRB 190530A: COATLI Optical Detection of the Fading Afterglow
  38. GRB 190530A: Swift-XRT afterglow detection
  39. GRB 190530A: GWAC-F30 optical detection
  40. GRB 190530A: OAJ optical detection
  41. Fermi GRB190530.43 Global MASTER-Net observations report
  42. GRB 190530A: Swift ToO observations
  43. GRB 190530A: MASTER OT detection
  44. IceCube-190504A: Kanata optical/NIR follow-up observations
  45. LIGO/Virgo S190425z: No counterpart candidate in Zadko-GRANDMA observations.
  46. LIGO/Virgo S190521r: CNEOST follow-up observations
  47. Fermi GRB190525.67 Global MASTER-Net observations report
  48. Fermi GRB190525.03 Global MASTER-Net observations report
  49. LIGO/Virgo S190521r: Kanata optical/NIR follow-up observations of the CNEOST Transient
  50. LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC-F30 observations.
  51. LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC observations.
  52. LIGO/Virgo S190521g: No optical counterpart from SVOM/GWAC-F30 observations.
  53. LIGO/Virgo S190521g: No optical counterpart from SVOM/GWAC observations.
  54. LIGO/Virgo S190524q Global MASTER-Net observations report
  55. LIGO/Virgo S190521r: No candidate counterparts from ATLAS observations of the skymap
  56. LIGO/Virgo S190521g: Upper limits from Insight-HXMT/HE observations
  57. LIGO/Virgo S190521r: RATIR Optical and NIR Observations of the CNEOST Transient
  58. LIGO/Virgo S190521r: No transient candidates from CALET observations
  59. LIGO/Virgo S190521g: Upper limits from CALET observations
  60. LIGO/Virgo S190521g: No Counterparts in DDOTI/OAN Optical Observations
  61. LIGO/Virgo S190521r: Coverage and upper limits from Fermi-LAT observations
  62. LIGO/Virgo S190521r: Upper limits from Fermi-GBM observations
  63. LIGO/Virgo S190521g : Upper limits from Fermi-GBM observations
  64. LIGO/Virgo S190521g: No candidate counterpart in Fermi-LAT observations
  65. LIGO/Virgo S190521r: Upper limits from AGILE-GRID observations
  66. LIGO/Virgo S190521r Global MASTER-Net observations report
  67. LIGO/Virgo S190521r: No counterpart candidate in AGILE-MCAL observations
  68. LIGO/Virgo S190521r: Coverage and upper limits from MAXI/GSC observations
  69. LIGO/Virgo S190517h : No counterpart candidate in TAROT-GRANDMA observations.
  70. LIGO/Virgo S190521r: No counterpart candidates in HAWC observations
  71. LIGO-Virgo S190521g: Upper Limits from AGILE-GRID observations
  72. IGO/Virgo S190521g: Coverage and upper limits from MAXI/GSC observations
  73. LIGO/Virgo S190521g: No counterpart candidates in INTEGRAL SPI/ACS & IBIS/PICsIT prompt observations
  74. LIGO/Virgo S190521g: No counterpart candidates in AGILE-MCAL observations
  75. LIGO/Virgo S190521g: No counterpart candidates in HAWC observations
  76. LIGO/Virgo S190521g Global MASTER-Net observations report
  77. S190519bj: No transient candidates from CALET observations
  78. LIGO/Virgo S190519bj: Upper limits from Insight-HXMT/HE observations
  79. LIGO/Virgo S190512at: SVOM/GWAC-F60A observations
  80. Fermi GRB190520.6 Global MASTER-Net observations report
  81. GRB 190519A: Swift/UVOT Upper Limits
  82. LIGO/Virgo S190519bj: MAXI/GSC Observations
  83. LIGO/Virgo S190519bj Global MASTER-Net observations report
  84. LIGO/Virgo S190519bj: Fermi GBM Observations
  85. LIGO-Virgo S190519bj: AGILE GRID observations
  86. LIGO/Virgo S190519bj: AGILE MCAL observations
  87. LIGO/Virgo S190517h: CALET Observations
  88. LIGO/Virgo S190426c: NICER X-ray Follow-Up of ZTF19aassfws
  89. LIGO/Virgo S190518bb Global MASTER-Net observations report
  90. Fermi GRB190517.81 Global MASTER-Net observations report
  91. GRB 190511A: Swift/UVOT further analysis
  92. LIGO/Virgo S190517h: Insight-HXMT/HE observations
  93. LIGO/Virgo S190517h: Fermi GBM Observations
  94. LIGO/Virgo S190517h: MAXI/GSC Observations
  95. LIGO/Virgo S190517h Global MASTER-Net observations report
  96. LIGO-Virgo S190517h: AGILE GRID observations
  97. LIGO/Virgo S190517h: AGILE MCAL observations
  98. Fermi GRB190517.1 Global MASTER-Net observations report
  99. GRB 190515B: Swift/UVOT Upper Limits
  100. LIGO/Virgo S190513bm: Swope follow-up 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