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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"

20480 results found.

  1. GRB 120923A: EVLA Observations
  2. GRB 120923A: GROND Upper limits
  3. GRB 120922A: Swift/UVOT Detection
  4. GRB 120923A: Swift/UVOT Upper Limit
  5. GRB 120922A: Swift/UVOT Observations
  6. GRB 120923A: Gemini afterglow detection, high-z candidate
  7. GRB 120922A: TAROT La Silla observatory optical observations
  8. GRB 120923A: TAROT La Silla observatory optical observations
  9. GRB 120922A: GROND afterglow candidate
  10. GRB 120919B: MASTER prompt optical observations
  11. GRB 120919A: Swift/UVOT Upper Limits
  12. GRB 120919A: Swift-XRT observations
  13. Swift Transient Swift J174510.8-262411: Swift-BAT refined analysis
  14. GRB 120913B: FRAM early follow up and detection
  15. GRB 120913B: REM NIR early time detection
  16. Continued Skynet/PROMPT observations of GRB120913B
  17. GRB 120913B: TAROT La Silla observatory optical photometry
  18. GRB 120913B: TAROT La Silla observatory optical detection
  19. Skynet/PROMPT observations of GRB120913B
  20. GRB 120907A: optical observations of ISON-Kislovodsk
  21. GRB 120911B: Fermi-LAT detection of a burst
  22. GRB 120911A: Swift/UVOT Upper Limits
  23. GRB 120911A: Faulkes Telescope North observations
  24. GRB 120911A: Swift-XRT observations
  25. GRB 120907A: SMA upper limits
  26. GRB 120908A: Swift Observations
  27. GRB 120909A: TAROT La Silla observatory optical observations
  28. GRB 120909A: Swift/UVOT Detection
  29. GRB 120908A: MAXI/GSC detection
  30. GRB 120909A: X-Shooter redshift 3.93
  31. GRB 120909A: GROND detection of the afterglow
  32. Skynet/PROMPT Observations of GRB120909A
  33. GRB 120909A: Swift detection of a burst
  34. GRB 120907A: EVLA observations
  35. GRB 120907A: Swift/UVOT Detection
  36. GRB 120907A: NOT optical observations
  37. GRB 120907A MASTER optical observations
  38. XMM observations of the short GRB120804A
  39. GRB 120802A: optical observations in CrAO
  40. GRB 120830A: Further Swift Observations
  41. GRB 120830A: Swift-XRT and UVOT observations
  42. Fermi trigger 368003226 : MASTER optical observations
  43. GRB 120819A: Swift/UVOT Upper Limits
  44. GRB 120817A: Swift/UVOT Upper Limits
  45. GRB 120817B: Deep limit on the optical afterglow from du Pont and Magellan observations
  46. GRB 120821A: Swift/XRT observations
  47. GRB 120821A: Swift/UVOT Upper Limits
  48. GRB 120821A: GROND upper limits
  49. GRB 120817B - PTF Observations
  50. GRB 120811C: optical observations
  51. GRB 120819A: MASTER final limits
  52. GRB 120819A: Bassano Bresciano Observatory optical observations
  53. GRB 120819A: GROND afterglow confirmation
  54. GRB 120819A: afterglow candidate from NOT
  55. GRB 120819A: MASTER optical observations
  56. GRB 120817B: Swift-XRT observations
  57. GRB 120811C: optical observations
  58. GRB 120815A: MASTER-ICATE observations
  59. GRB 120817B: LCO Optical Observations
  60. GRB 120815A: Swift/UVOT Detection of the Optical Afterglow
  61. GRB 120816A: Bassano Bresciano Observatory optical observations
  62. GRB 120817A: FTN and FTS observations
  63. GRB 120817A: Swift-XRT observations
  64. GRB 120816A: BOOTES-2 observations
  65. GRB120816A: OPTIMA discovery of optical counterpart
  66. GRB 120816A: TAROT Calern observatory optical observations
  67. GRB 120815A: GROND afterglow candidate
  68. GRB 120815A: Swift-XRT observations
  69. GRB 120815A: TAROT La Silla observatory optical observations
  70. GRB 120804A: Possible temporal break in the X-ray light-curve
  71. GRB 120811A: Swift/XRT-UVOT Obseravations
  72. GRB120804A: Chandra observations and afterglow detection
  73. GRB 120805A: optical afterglow confirmation from the NOT
  74. GRB 120811C: EVLA Observations
  75. GRB 120811C: RTT150 optical observations
  76. GRB 120811C: MASTER-Tunka OT observations
  77. GRB 120811C: NOT redshift
  78. GRB 120811C: Bassano Bresciano Observatory optical observations
  79. GRB 120811C: Swift/UVOT Detection
  80. GRB 120811C: RTT150 optical observations
  81. GRB 120811C: TAROT Calern observatory optical observations
  82. GRB 120811C: MASTER-Amur observations of fading OT
  83. GRB 120807A: Swift/UVOT Upper Limits
  84. GRB 120714B: GROND/FORS2 detection of a supernova
  85. GRB 120804A: ATCA 34GHz upper limit
  86. GRB 120802A: optical observations
  87. GRB 120804A: Gemini-North detection of an optical afterglow and putative host galaxy
  88. GRB 120807A: TAROT La Silla observatory optical observations
  89. GRB 120804A: ATCA 34GHz upper limit
  90. GRB 120805A: Swift/UVOT Upper Limits
  91. GRB 120802A: Swift/UVOT Upper Limits
  92. GRB 120805A: 1.23m CAHA observations
  93. GRB120805A: Liverpool Telescope observations
  94. GRB 120805A: TAROT Calern observatory optical observations
  95. GRB 120804A: EVLA Detection
  96. GRB 120804A: Gemini-North observations
  97. GRB 120804A: Swift/UVOT Upper Limits
  98. GRB 120804A: GROND upper limits
  99. GRB 120802A: EVLA Observations
  100. GRB 120803A: Swift-XRT Observations

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