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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"

20960 results found.

  1. GRB 120911B: Fermi-LAT detection of a burst
  2. GRB 120911A: Swift/UVOT Upper Limits
  3. GRB 120911A: Faulkes Telescope North observations
  4. GRB 120911A: Swift-XRT observations
  5. GRB 120907A: SMA upper limits
  6. GRB 120908A: Swift Observations
  7. GRB 120909A: TAROT La Silla observatory optical observations
  8. GRB 120909A: Swift/UVOT Detection
  9. GRB 120908A: MAXI/GSC detection
  10. GRB 120909A: X-Shooter redshift 3.93
  11. GRB 120909A: GROND detection of the afterglow
  12. Skynet/PROMPT Observations of GRB120909A
  13. GRB 120909A: Swift detection of a burst
  14. GRB 120907A: EVLA observations
  15. GRB 120907A: Swift/UVOT Detection
  16. GRB 120907A: NOT optical observations
  17. GRB 120907A MASTER optical observations
  18. XMM observations of the short GRB120804A
  19. GRB 120802A: optical observations in CrAO
  20. GRB 120830A: Further Swift Observations
  21. GRB 120830A: Swift-XRT and UVOT observations
  22. Fermi trigger 368003226 : MASTER optical observations
  23. GRB 120819A: Swift/UVOT Upper Limits
  24. GRB 120817A: Swift/UVOT Upper Limits
  25. GRB 120817B: Deep limit on the optical afterglow from du Pont and Magellan observations
  26. GRB 120821A: Swift/XRT observations
  27. GRB 120821A: Swift/UVOT Upper Limits
  28. GRB 120821A: GROND upper limits
  29. GRB 120817B - PTF Observations
  30. GRB 120811C: optical observations
  31. GRB 120819A: MASTER final limits
  32. GRB 120819A: Bassano Bresciano Observatory optical observations
  33. GRB 120819A: GROND afterglow confirmation
  34. GRB 120819A: afterglow candidate from NOT
  35. GRB 120819A: MASTER optical observations
  36. GRB 120817B: Swift-XRT observations
  37. GRB 120811C: optical observations
  38. GRB 120815A: MASTER-ICATE observations
  39. GRB 120817B: LCO Optical Observations
  40. GRB 120815A: Swift/UVOT Detection of the Optical Afterglow
  41. GRB 120816A: Bassano Bresciano Observatory optical observations
  42. GRB 120817A: FTN and FTS observations
  43. GRB 120817A: Swift-XRT observations
  44. GRB 120816A: BOOTES-2 observations
  45. GRB120816A: OPTIMA discovery of optical counterpart
  46. GRB 120816A: TAROT Calern observatory optical observations
  47. GRB 120815A: GROND afterglow candidate
  48. GRB 120815A: Swift-XRT observations
  49. GRB 120815A: TAROT La Silla observatory optical observations
  50. GRB 120804A: Possible temporal break in the X-ray light-curve
  51. GRB 120811A: Swift/XRT-UVOT Obseravations
  52. GRB120804A: Chandra observations and afterglow detection
  53. GRB 120805A: optical afterglow confirmation from the NOT
  54. GRB 120811C: EVLA Observations
  55. GRB 120811C: RTT150 optical observations
  56. GRB 120811C: MASTER-Tunka OT observations
  57. GRB 120811C: NOT redshift
  58. GRB 120811C: Bassano Bresciano Observatory optical observations
  59. GRB 120811C: Swift/UVOT Detection
  60. GRB 120811C: RTT150 optical observations
  61. GRB 120811C: TAROT Calern observatory optical observations
  62. GRB 120811C: MASTER-Amur observations of fading OT
  63. GRB 120807A: Swift/UVOT Upper Limits
  64. GRB 120714B: GROND/FORS2 detection of a supernova
  65. GRB 120804A: ATCA 34GHz upper limit
  66. GRB 120802A: optical observations
  67. GRB 120804A: Gemini-North detection of an optical afterglow and putative host galaxy
  68. GRB 120807A: TAROT La Silla observatory optical observations
  69. GRB 120804A: ATCA 34GHz upper limit
  70. GRB 120805A: Swift/UVOT Upper Limits
  71. GRB 120802A: Swift/UVOT Upper Limits
  72. GRB 120805A: 1.23m CAHA observations
  73. GRB120805A: Liverpool Telescope observations
  74. GRB 120805A: TAROT Calern observatory optical observations
  75. GRB 120804A: EVLA Detection
  76. GRB 120804A: Gemini-North observations
  77. GRB 120804A: Swift/UVOT Upper Limits
  78. GRB 120804A: GROND upper limits
  79. GRB 120802A: EVLA Observations
  80. GRB 120803A: Swift-XRT Observations
  81. GRB 120802A Gemini-N redshift
  82. GRB 120802A: APEX/LABOCA submm observations
  83. GRB 120802A: MASTER optical observations
  84. GRB 120802A: optical uper limit in ISON-NM observatory
  85. GRB 120729A: JCMT SCUBA-2 sub-mm observation
  86. GRB 120729A: break in the optical light curve
  87. GRB 120729A: Optical observations from OSN, BOOTES1/2 and IAC80
  88. GRB 120729A: RTT150 optical observations
  89. GRB 120729A: EVLA Observations
  90. Virtual Telescope observations of GRB 120729A
  91. GRB 120729A: Early RAPTOR Observations
  92. GRB 120729A: UKIRT Observation
  93. T100 observations of GRB 120729A
  94. GRB 120728A: GROND Afterglow discovery
  95. GRB 120729A: Swift/UVOT Detection
  96. GRB 120729A: Xinglong TNT optical upper limit
  97. GRB 120728A: Swift/UVOT Upper Limits
  98. GRB 120729A Gemini-N redshift
  99. GRB120729A - Faulkes Telescope North Optical Afterglow Candidate
  100. GRB 120728A: GROND observations

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