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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"

44399 results found.

  1. EP240802a: correction of EP-WXT trigger time in GCN 37019
  2. GRB 240805A: Swift detection of a burst
  3. GRB 240805A: Fermi GBM Final Real-time Localization
  4. Fermi GRB 240804A: Global MASTER-Net observations report
  5. EP240802a: Montarrenti Observatory optical upper limit
  6. GRB 240804A: Fermi GBM Final Real-time Localization
  7. Fermi trigger No 744459130: Global MASTER-Net observations report
  8. IPN triangulation of GRB 240802A / EP 240802a
  9. Fermi Gamma-ray Burst Monitor trigger 744459130/240804425 is not a GRB
  10. EP240801a: Osservatorio Astronomico Nastro Verde upper limit
  11. EP240802A: Bassano Bresciano Observatory upper limit
  12. GRB 240802A: SVOM/GRM observation
  13. EP240802a: Time coincidence with GRB 240802A and optical upper limits with Kinder observations
  14. Fermi trigger No 744278264: Global MASTER-Net observations report
  15. EP240802a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  16. GRB 240802A: AstroSat CZTI detection of a long burst
  17. EP240801a: further SAO RAS optical observations
  18. EP240801a: optical observations at CrAO and AbAO
  19. EP240801a: GRANDMA and Kilonova-Catcher optical observations
  20. EP240801a: Leavitt Observatory optical observations
  21. EP240801a: GTC spectroscopy and absorption redshift
  22. EP240801a: SAO RAS optical observations
  23. GRB 240801B: AstroSat CZTI Updated classification - likely a solar flare
  24. EP240801a: JinShan optical observations
  25. GRB 240727C: SVOM/GRM observation
  26. EP240801a: NOT optical observations
  27. EP240801a: follow-up observation with LCOGT
  28. Fermi GBM trigger 744179961 / 240801194 can not be confirmed as a GRB
  29. GRB 240730A: Swift-BAT refined analysis
  30. EP240801a: GSP follow-up observations of the candidate counterpart
  31. Fermi trigger No 744204856: Global MASTER-Net observations report
  32. EP240801a: Kinder follow-up observations of the candidate counterpart
  33. EP240708a: Kinder follow-up observations of the candidate counterpart (duplicate submission of GCN 37002)
  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 240730C: AstroSat CZTI detection of a long burst
  42. GRB 240731A: Fermi GBM Final Localization
  43. Fermi trigger No 744128417: Global MASTER-Net observations report
  44. Fermi trigger No 744083370: Global MASTER-Net observations report
  45. GRB 240731A: AstroSat CZTI detection
  46. GRB 240730A: Osservatorio Astronomico Nastro Verde upper limit
  47. GRB240730A: BOOTES-5/JGT early optical upper limit
  48. Fermi Gamma-ray Burst Monitor trigger 744061103/240730818 is not a GRB
  49. Fermi GRB 240730B: Global MASTER-Net observations report
  50. GRB 240730B: Fermi GBM Final Real-time Localization
  51. Swift GRB 240730A: Global MASTER-Net observations report
  52. GRB 240730A: Swift-XRT refined Analysis
  53. GRB 240715A: Swift-XRT afterglow detection
  54. GRB 240730A: KAIT Optical Upper Limit
  55. GRB 240727C: GRBAlpha detection
  56. GRB 240730A: Swift/UVOT Upper Limits
  57. GRB 240730A: Enhanced Swift-XRT position
  58. GRB 240730A: Swift detection of a burst
  59. Fermi trigger No 743953682: Global MASTER-Net observations report
  60. GRB 240727A: Swift-BAT refined analysis
  61. Fermi Gamma-ray Burst Monitor trigger 743953682/240729575 is not a GRB
  62. LIGO/Virgo/KAGRA S240615dg: GRAWITA wide-field optical observations
  63. GRB 240727A: observations of optical counterpart.
  64. GRB 240727B: Swift-XRT observations
  65. Fermi GRB 240727A: Global MASTER-Net observations report
  66. GRB 240727A: Swift/UVOT detection
  67. Fermi trigger No 743868421: Global MASTER-Net observations report
  68. Fermi Gamma-ray Burst Monitor trigger 743868421/240728588 is not a GRB
  69. GRB 240727A: Osservatorio Astronomico Nastro Verde upper limit
  70. EP-WXT trigger 01709002661 is not a real source
  71. GRB 240727A: NOT optical observation
  72. GRB 240727A: JinShan optical upper limits
  73. GRB 240727A Bassano Bresciano Observatory upper limit
  74. GRB 240727D: Correction to the GRB name in GCN 36958
  75. GRB 240727A: Fermi GBM Final Real-time Localization
  76. GRB 240727C: AstroSat CZTI detection of a long burst
  77. GRB 240727A: Swift-XRT refined Analysis
  78. GRB 240720B: GRBAlpha detection
  79. GRB 240718A: GRBAlpha detection
  80. GRB 240710B: GRBAlpha detection
  81. GRB 240627A: GRBAlpha detection
  82. Fermi GRB 240726A: Global MASTER-Net observations report
  83. GRB 240727A: Enhanced Swift-XRT position
  84. GRB 240727B: Fermi GBM Observation
  85. Swift GRB240727.16: Global MASTER-Net observations report
  86. GRB240529A: VIRT optical transient detection
  87. GRB 240727B: Swift ToO observations
  88. GRB 240727B: Swift/BAT-GUANO arcminute localization of a long burst
  89. GRB 240726A: SVOM/GRM observation
  90. GRB 240727B: AstroSat CZTI detection
  91. GRB 240726B: AstroSat CZTI detection of a short burst
  92. GRB240727A: Skynet Optical Afterglow Observations
  93. GRB 240727A: TRT optical afterglow detection
  94. GRB 240727A: KAIT Optical Afterglow Candidate
  95. GRB 240727A: Swift detection of a burst
  96. GRB 240726A: AstroSat CZTI detection of a short burst
  97. IceCube-240725A: Upper limits from a search for additional neutrino events in IceCube
  98. GRB 240726A: Fermi GBM Final Real-time Localization
  99. Fermi-LAT gamma-ray observations of IceCube-240725A
  100. IceCube Alert 240725.22: Global MASTER-Net observations report

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