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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"

20955 results found.

  1. GRB 130513A: Swift/UVOT Upper Limits
  2. GRB 130514A: Swift/UVOT Upper Limits
  3. GRB 130513A: GROND observations
  4. GRB 130514A: GROND optical-NIR afterglow discovery and photo-z
  5. GRB 130514A: P60 Observations
  6. GRB 130427A: Tautenburg 2nd epoch: No break, no clear SN
  7. GRB130508A: MASTER-Net optical observations
  8. GRB 130511A: Kanata/HOWPol optical observation
  9. GRB 130508A: Swift/UVOT Upper Limits
  10. GRB 130427A: host galaxy observations
  11. GRB 130508A: RATIR Optical and NIR Observations
  12. GRB 130427A: Keck/LRIS Observations
  13. GRB 130427A: Ten nights of Skynet/PROMPT/GORT observations
  14. GRB 130427A: Continued RATIR Optical and NIR Observations
  15. GRB 130505B: Further Swift observations
  16. GRB 130427A: Excess optical emission consistent with an emerging supernova
  17. GRB 130427A: Amateur observations from Sweden
  18. GRB 130505A: RATIR Optical and NIR Observations
  19. GRB 130505B: Swift Candidate Afterglow
  20. GRB 130505A: Tautenburg afterglow observations
  21. GRB 130427A: Tautenburg afterglow observations
  22. GRB 130427A: RHESSI observations
  23. GRB 130504C: further Swift-XRT observations
  24. GRB 130505A: optical observations
  25. GRB 130504C: Swift-XRT observations
  26. GRB 130427A: optical observations in CrAO
  27. Swift/UVOT observations of GRB130505A
  28. GRB 130505A: iTelescope T12 optical observations
  29. GRB 130505A: Xinglong TNT optical observations
  30. GRB 130505A; Weihai optical observations
  31. GRB 130504A: IAC80 optical candidate
  32. GRB 130504A: Bassano Bresciano Observatory optical upper limit
  33. GRB 130504A: Swift/UVOT Upper Limits
  34. GRB 130502B: possible TNG counterpart
  35. GRB 130427A: Non-observation of VHE emission with HAWC
  36. GRB130502A: MASTER-Net optical observations
  37. GRB 130502B: Swift/UVOT Upper Limits
  38. GRB 130502A: Swift/UVOT Upper Limits
  39. GRB 130502B: P60 Observations
  40. GRB 130502B Swift-XRT observations
  41. GRB 130502A: RATIR Optical and NIR Observations
  42. GRB 130427A: Pan-STARRS 1 optical observations
  43. GRB 130418A: TNG NIR observations
  44. GRB 130502A: OSN and IAC80 I-band observations
  45. GRB 130502A: z-band observations from GTC
  46. GRB 130502A: TNG candidate counterpart
  47. GRB 130502A: T100 Observations
  48. GRB 130427A: Predictions about the occurrence of a supernova
  49. GRB 130427A: KAIT optical observations
  50. GRB 130427A: SARA-N optical observations
  51. GRB 130427A: VLA 20 GHz detection
  52. GRB 130427A: ABT optical observations
  53. GRB 130427A: GMRT radio detection
  54. GRB 130427A: Continued GMG optical observations
  55. GRB 130427A: Nishi-Harima Optical Spectroscopic Observations
  56. GRB 130427A: Continued RATIR Optical and NIR Observations
  57. GRB 130427A: Challis Observatory optical observations
  58. GRB 130427A: Continued Skynet/PROMPT Observations
  59. GRB 130427A: further GMG observations
  60. GRB 130427A: Continued RATIR Optical and NIR Observations
  61. GRB 130425: MASTER-Net optical observations
  62. GRB 100728A: GROND host detection and X-shooter redshift
  63. GRB 130427A: Skynet/PROMPT Observations
  64. GRB 130427B: RATIR Optical and NIR Observations
  65. GRB 130427A: Nishi-Harima NIR Observations
  66. GRB 130427A: CARMA 3mm observations
  67. GRB 130427A optical time series
  68. GRB 130427A, Optical Observations
  69. GRB 130427A: Continued iTelescope T21 optical observations
  70. Konus-Wind observation of GRB 130427A
  71. GRB 130427A: SPI-ACS/INTEGRAL observations
  72. GRB 130427A: Continued RATIR Optical and NIR Observations
  73. GRB 130427A: CARMA 85 GHz detection
  74. GRB 130427A: SNUO/SOAO/BOAO Observation
  75. GRB 130427A: VLA 5 GHz detection
  76. GRB 130427A: NOT optical photometry and redshift
  77. GRB 130427A: T100 observations
  78. GRB 130427A: optical observations in CrAO
  79. GRB130427A: Swift/UVOT followup observations of an Optical Afterglow
  80. GRB 130427A: Zadko observatory - Gingin optical observations
  81. GRB 130427A: GMG optical observation
  82. GRB 130427A: Optical Observations
  83. GRB 130427A: RATIR Optical and NIR Observations
  84. GRB 130427A: Weihai optical observations
  85. GRB 130427A: iTelescope T11 optical observations
  86. GRB 130427A: Continued P60 follow-up of an extremely bright optical afterglow
  87. GRB 130427A: Gemini-North redshift
  88. GRB 130427A: PAIRITEL NIR Detections
  89. GRB 130427A: Faulkes Telescope North detection
  90. GRB 130427A: P60 early detection
  91. GRB 130427A: early optical observations
  92. GRB 130427A: P60 early nondetection
  93. GRB 130420A: Continued Skynet/GORT Observations/Detections
  94. GRB 130420B: CARMA and VLA radio observations
  95. Trigger 554491: Swift detection of a spike possibly from Sgr A*
  96. GRB 130420A: Continued RATIR Optical and NIR Observations
  97. GRB 130420A: ROTSE-III data analysis
  98. GRB 130420A: Continued RATIR Optical and NIR Observations
  99. GRB 130418A: Continued RATIR Optical and NIR Observations
  100. GRB 130420A: Early RAPTOR Simultaneous Multi-Color Observations

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