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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"

27254 results found.

  1. GRB 240805A: Fermi-LAT detection
  2. EP240804a: VLT/X-shooter spectroscopic redshift
  3. EP240804a: LCOGT optical counterpart detection
  4. EP-WXT trigger 00109017646 is not a real source
  5. EP240804a: NOT optical counterpart detection
  6. EP240804a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  7. EP240802a: correction of EP-WXT trigger time in GCN 37019
  8. GRB 240805A: Swift detection of a burst
  9. GRB 240805A: Fermi GBM Final Real-time Localization
  10. Fermi GRB 240804A: Global MASTER-Net observations report
  11. GRB 240804A: Fermi GBM Final Real-time Localization
  12. Fermi trigger No 744459130: Global MASTER-Net observations report
  13. Fermi Gamma-ray Burst Monitor trigger 744459130/240804425 is not a GRB
  14. EP240802A: Bassano Bresciano Observatory upper limit
  15. GRB 240802A: SVOM/GRM observation
  16. EP240802a: Time coincidence with GRB 240802A and optical upper limits with Kinder observations
  17. Fermi trigger No 744278264: Global MASTER-Net observations report
  18. EP240802a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  19. GRB 240802A: AstroSat CZTI detection of a long burst
  20. EP240801a: optical observations at CrAO and AbAO
  21. EP240801a: GRANDMA and Kilonova-Catcher optical observations
  22. EP240801a: Leavitt Observatory optical observations
  23. EP240801a: GTC spectroscopy and absorption redshift
  24. GRB 240801B: AstroSat CZTI Updated classification - likely a solar flare
  25. EP240801a: JinShan optical observations
  26. GRB 240727C: SVOM/GRM observation
  27. EP240801a: NOT optical observations
  28. EP240801a: follow-up observation with LCOGT
  29. Fermi GBM trigger 744179961 / 240801194 can not be confirmed as a GRB
  30. GRB 240730A: Swift-BAT refined analysis
  31. EP240801a: GSP follow-up observations of the candidate counterpart
  32. Fermi trigger No 744204856: Global MASTER-Net observations report
  33. EP240801a: Kinder follow-up observations of the candidate counterpart
  34. EP240801a: KAIT optical counterpart observations
  35. EP240801a: GMG observation
  36. EP240801a: TRT optical counterpart detection
  37. EP240801a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  38. GRB 240801B: AstroSat CZTI detection of a bright long burst
  39. Fermi GRB 240801A: Global MASTER-Net observations report
  40. GRB 240801A: Fermi GBM Final Real-time Localization
  41. GRB 240731A: Fermi GBM Final Localization
  42. Fermi trigger No 744128417: Global MASTER-Net observations report
  43. Fermi trigger No 744083370: Global MASTER-Net observations report
  44. GRB 240731A: AstroSat CZTI detection
  45. GRB 240730A: Osservatorio Astronomico Nastro Verde upper limit
  46. GRB240730A: BOOTES-5/JGT early optical upper limit
  47. Fermi Gamma-ray Burst Monitor trigger 744061103/240730818 is not a GRB
  48. Fermi GRB 240730B: Global MASTER-Net observations report
  49. GRB 240730B: Fermi GBM Final Real-time Localization
  50. Swift GRB 240730A: Global MASTER-Net observations report
  51. GRB 240730A: Swift-XRT refined Analysis
  52. GRB 240727C: GRBAlpha detection
  53. GRB 240730A: Swift/UVOT Upper Limits
  54. GRB 240730A: Swift detection of a burst
  55. Fermi trigger No 743953682: Global MASTER-Net observations report
  56. GRB 240727A: Swift-BAT refined analysis
  57. Fermi Gamma-ray Burst Monitor trigger 743953682/240729575 is not a GRB
  58. LIGO/Virgo/KAGRA S240615dg: GRAWITA wide-field optical observations
  59. GRB 240727A: observations of optical counterpart.
  60. Fermi GRB 240727A: Global MASTER-Net observations report
  61. GRB 240727A: Swift/UVOT detection
  62. Fermi trigger No 743868421: Global MASTER-Net observations report
  63. Fermi Gamma-ray Burst Monitor trigger 743868421/240728588 is not a GRB
  64. GRB 240727A: Osservatorio Astronomico Nastro Verde upper limit
  65. EP-WXT trigger 01709002661 is not a real source
  66. GRB 240727A Bassano Bresciano Observatory upper limit
  67. GRB 240727D: Correction to the GRB name in GCN 36958
  68. GRB 240727A: Fermi GBM Final Real-time Localization
  69. GRB 240727C: AstroSat CZTI detection of a long burst
  70. GRB 240727A: Swift-XRT refined Analysis
  71. GRB 240720B: GRBAlpha detection
  72. GRB 240718A: GRBAlpha detection
  73. GRB 240710B: GRBAlpha detection
  74. Fermi GRB 240726A: Global MASTER-Net observations report
  75. GRB 240727B: Fermi GBM Observation
  76. Swift GRB240727.16: Global MASTER-Net observations report
  77. GRB 240727B: Swift/BAT-GUANO arcminute localization of a long burst
  78. GRB 240726A: SVOM/GRM observation
  79. GRB 240727B: AstroSat CZTI detection
  80. GRB240727A: Skynet Optical Afterglow Observations
  81. GRB 240727A: Swift detection of a burst
  82. GRB 240726A: Fermi GBM Final Real-time Localization
  83. IceCube Alert 240725.22: Global MASTER-Net observations report
  84. Swift Trigger 1244778 is not a GRB
  85. Swift GRB240725.11: Global MASTER-Net observations report
  86. GRB 240720A: Swift-BAT refined analysis
  87. Fermi trigger No 743418632: Global MASTER-Net observations report
  88. Fermi trigger No 743315411: Global MASTER-Net observations report
  89. LIGO/Virgo/KAGRA S240716b: Upper limits from Swift/BAT-GUANO
  90. LIGO/Virgo/KAGRA S240703ad: Upper limits from Swift/BAT-GUANO
  91. Fermi trigger No 743345551: Global MASTER-Net observations report
  92. Fermi Gamma-ray Burst Monitor trigger 743271526/240721680 is not a GRB
  93. Fermi trigger No 743219692: Global MASTER-Net observations report
  94. IceCube Alert 240721.68: Global MASTER-Net observations report
  95. Fermi Gamma-ray Burst Monitor trigger 743243582/240721356 (GRB 240721A) is not a GRB
  96. GRB 240720B: SVOM/GRM observation
  97. GRB 240721A: Fermi GBM Final Real-time Localization
  98. GRB 240720B: AstroSat CZTI detection of a short burst
  99. Fermi GRB 240720A: Global MASTER-Net observations report
  100. GRB 240720A: AstroSat CZTI detection

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