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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"

3763 results found.

  1. GRB 150728A: AAO optical observations
  2. GRB 150728A: FTN observations
  3. GRB 150727A: LCOGT-Cerro Tololo observations
  4. GRB 150727A: VLT/X-shooter redshift
  5. Konus-Wind observation of GRB 150725A
  6. Swift IGR J00291+5934: MASTER Optical flare detection
  7. GRB 150720A: Swift-XRT refined Analysis
  8. GRB 150711A: Fermi GBM detection
  9. GRB 150710B refined analysis
  10. GRB 150711A: Swift detection of a burst
  11. Konus-Wind observation of GRB 150710A (Swift trigger 648437)
  12. Swift trigger 648437: A GRB or a burst from 1RXS J125754.7+141850
  13. Fermi Gamma-ray Burst Monitor Trigger bn150628857 is not a GRB
  14. V404 Cyg: MASTER Swift, Integral alert observations
  15. Swift Trigger 645340: a possible GRB
  16. Trigger 645176: Swift detection of V404 Cyg
  17. GRB 150616A: Swift-BAT refined analysis
  18. Optical follow-up of Swift trigger on V404 Cyg
  19. GRB 150615A: Swift detection of a burst
  20. GRB 150530B detected in ground analysis of BAT data
  21. GRB 150513A: Swift detection of a burst
  22. GRB 150430A: MAXI/GSC detection
  23. GRB 150430A: Swift detection of a burst
  24. GRB 150428B: IRSF NIR upper limits
  25. GRB 150428C: MASTER-net automatic optical inspection
  26. GRB 150428B: MASTER-net prompt optical observation
  27. GRB 150428A: MASTER-net early optical observation
  28. GRB 150428A: Danish1.56m optical observations
  29. GRB 150428A: P60 observations
  30. GRB 150428A: GROND Dark Burst Host Candidate
  31. GRB 150424B: Fermi GBM detection
  32. GRB 150423A: Swift detection of a short burst
  33. GRB 150413A: RTT150 optical observations
  34. GRB 150413A: MITSuME Akeno Optical observation
  35. GRB 150413A: SAO RAS observations
  36. GRB 150407A: Swift detection of a possible burst
  37. GRB 150323C: Khureltogot optical observations
  38. GRB 141121A: GMG observation
  39. GRB 141220A: GMG observation limit
  40. GRB 150323C: Nishi-Harima NIR Observations
  41. Konus-Wind observation of GRB 150323B
  42. GRB 150323B: Fermi GBM observation
  43. GRB 150323C: MASTER-net optical observation
  44. GRB 150323B detected in ground analysis of Swift-BAT data
  45. GRB 150318A: Swift detection of a burst
  46. GRB 150317A: Swift-BAT refined analysis
  47. GRB 150317A: Swift detection of a burst
  48. GRB 150301A: Swift detection of a short burst or new SGR
  49. Konus-Wind observation of GRB 150220A
  50. GRB 150213B, the review of the sky area in plate archives
  51. GRB 150212A: Khureltogot optical upper limit
  52. GRB 150203A: GROND Upper limits
  53. GRB 150128A: MASTER OT detction during inspection
  54. GRB 150123A: MASTER inspection
  55. IPN Triangulation of GRB 150127B
  56. Trigger 626581: Swift detection of GRO J1008-57
  57. GRB 150110A: MAXI/GSC detection
  58. GRB 150101A: Fermi GBM detection
  59. GRB 150101A: Swift detection of a short burst
  60. GRB 141225A: MASTER-SAAO OT light curve
  61. GRB 141225A: MASTER-SAAO first OT detection
  62. Konus-Wind observation of GRB 141222A
  63. Fermi Gamma-ray Burst Monitor trigger 440728127 / 141220020 is not a GRB
  64. Konus-Wind observation of GRB 141215A
  65. GRB 141212A iTelescope observation
  66. GRB 141212A: MITSuME Akeno upper limits
  67. GRB 141207A: Swift-UVOT Observations
  68. GRB 141207A: Swift-XRT observations
  69. GRB 141121A: MITSuME Ishigakijima Optical Observation after 7 days
  70. IPN Triangulation of GRB 141125A (short/hard)
  71. IPN Triangulation of GRB 141118A
  72. Swift Trigger 618402: probable noise event
  73. GRB 141109A: MITSuME Ishigakijima upper limits
  74. GRB 141109B: Swift-BAT refined analysis
  75. Konus-Wind observation of GRB 141102A
  76. GRB 141029A: MAXI/GSC detection
  77. GRB 141028A: Fermi GBM detection
  78. GRB 141028A: Fermi-LAT detection
  79. GRB 141020A: Mondy optical observations
  80. GRB 141017A: Swift detection of a burst
  81. GRB 141004A: Fermi GBM observation
  82. GRB 141005A: P60 probable afterglow deteaction
  83. GRB 140928A: MAXI-GSC detection
  84. GRB 140930B: MASTER early optical observations
  85. GRB 140928A: Fermi GBM detection
  86. GRB 140928A: Fermi-LAT detection
  87. GRB 140916B: iPTF Optical Observations
  88. GRB 140907A: Continued DCT Observations
  89. GRB 140907A : Optical observations from Nanshan
  90. GRB 140828A: Fermi GBM observation
  91. GRB 140824A: Swift detection of a burst
  92. Fermi trigg_num 430148973: bright OT inside large error box!
  93. GRB 140818A: Correction to GCN 16702
  94. GRB 140808A: optical afterglow candidate iPTF14eag
  95. GRB 140713A: 10.4-m GTC deep optical observation
  96. GRB 140706A: Swift-BAT refined analysis
  97. Pre-discovery observations of SGR 1935+2154 in Swift archival data
  98. GRB 140629A: SAO RAS monitoring
  99. Fermi 425667201: optical counterpart search
  100. Swift Trigger 602668 is probably not an astrophysical source

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