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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"

17850 results found.

  1. GRB090305: GMOS-S Candidate Optical Afterglow
  2. GRB 090305: Swift detection of a short burst
  3. GRB 081211B: Nearby cluster
  4. GRB090217: XRT analysis
  5. SGR activity seen by BAT during ICSP Ionospheric Events
  6. VLA radio upper limit on GRB 090205
  7. GRB 090205: Swift/UVOT Upper Limits
  8. GRB 090205: GROND observations and photometric redshift estimate
  9. GRB 090205: VLT candidate afterglow
  10. GRB 090205: Enhanced Swift-XRT position
  11. GRB 090205: Swift detection of a burst
  12. GRB 080319B: IceCube upper limit on high-energy neutrino flux
  13. ICSP VLF observation of the signatures of SGR/AXP 1E1547.0-5408 bursts
  14. GRB090201: Swift UVOT upper limits
  15. GRB 090201: object inside the enhanced XRT error circle
  16. GRB 090201: Enhanced Swift-XRT position
  17. GRB 090201: VLT NIR observations
  18. GRB 090201: VLT afterglow candidate
  19. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  20. GRB 090201: ROTSE-III Optical Limits
  21. GRB 090126A: Swift/UVOT Upper Limits
  22. Suzaku ToO Observation of AXP 1E 1547.0-5408
  23. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  24. GRB 090102: HST observations and host galaxy
  25. GRB 090118: no afterglow candidate
  26. GRB 090123: GROND detection
  27. GRB 090123: Swift/UVOT Observations
  28. GRB090123: Enhanced Swift-XRT position
  29. GRB 090123: Swift detection of a burst
  30. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  31. Trigger 340734: Swift detection of a possible short burst
  32. GRB 090118: Subaru NIR Observation
  33. GRB 090118: KPNO 4m 2nd Epoch Observations
  34. GRB 090118 (BATSS): GRT Optical Observation
  35. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  36. GRB090118 Swift/UVOT upper limits
  37. GRB 090118: GROND Upper Limits
  38. GRB 090118: Possible burst detection from Swift-BAT slew data
  39. GRB 090117: GROND Upper Limits
  40. GRB090117 Swift/UVOT upper limits
  41. GRB090117: Swift-XRT detection of a possible candidate afterglow
  42. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  43. GRB 090113: Swift UVOT upper limits
  44. GRB 090113: GROND Upper Limits
  45. GRB 090113: Observations from NOT
  46. GRB 090113: Enhanced Swift-XRT position
  47. GRB 090113: ROTSE-III Optical Limits
  48. GRB 090112B: Fermi GBM Detection
  49. GRB 090113: Swift detection of a burst
  50. GRB 090111, Swift-BAT refined analysis
  51. GRB 090111: Swift UVOT Upper Limits
  52. GRB 090111: Enhanced Swift-XRT position
  53. GRB 090111: Swift detection of a burst
  54. GRB 090102: WSRT Radio Observations
  55. GRB 090107B: Swift XRT afterglow confirmation
  56. GRB 090107B: Swift/UVOT Observations
  57. GRB 090107B: Swift-XRT detection of possible afterglow
  58. VLA radio upper limit on GRB 090102
  59. GRB 090102: GRT Optical Observation
  60. Swift triggered on the HMXB 1A 1118-61
  61. GRB 090102: P60 Imaging and P200 Spectroscopy
  62. GRB 090102 Observations from IAC80
  63. GRB 090102: GROND observations of the optical afterglow
  64. GRB 090102: NOT redshift
  65. GRB 090102: Enhanced Swift-XRT position
  66. GRB 090102: REM observations of a bright afterglow
  67. GRB 090102: Swift detection of a burst with an optical counterpart
  68. GRB 090102: TAROT Calern observatory optical observations
  69. GRB 081230: GROND confirmation of the afterglow
  70. GRB081230: Swift-XRT refined analysis
  71. GRB 081230 Swift/UVOT Observations
  72. GRB 081230: Enhanced Swift-XRT position
  73. GRB 081230: Swift detection of a burst
  74. GRB 081228, Swift-BAT refined analysis
  75. VLA radio detection of GRB 081221
  76. GRB 081228: Swift/UVOT Upper Limits
  77. GRB 081228: Swift-XRT Team refined analysis
  78. GRB 081228: detection by GROND
  79. GRB 081228: Enhanced Swift-XRT position
  80. GRB 081228: TAROT Calern observatory optical observations
  81. GRB 081228: Swift detection of a burst
  82. VLA radio observation of GRB 081221
  83. GRB 081226B: Swift XRT and UVOT upper limits
  84. GRB 081226: Swift-XRT refined analysis
  85. GRB 081226A: Swift UVOT Upper Limits
  86. GRB 081226: GROND afterglow candidate
  87. GRB 081226: ROTSE-III Optical Limits
  88. GRB 081226: Swift detection of a possible short-hard burst
  89. GRB 080810: optical observations
  90. GRB 081211B: optical observations
  91. GRB 081224: Swift-XRT observation
  92. GRB 081222: MITSuME optical observation
  93. GRB 081221: GROND observations
  94. GRB 081222:Optical afterglow observation
  95. VLA radio upper limit on GRB 081222
  96. GRB 081222: Fermi GBM observation
  97. GRB 081221: Probable host galaxy in Keck imaging
  98. GRB 081222, Swift-BAT refined analysis
  99. GRB081222 optical limit by "Pi of the Sky"
  100. GRB 081222: Swift XRT refined analysis

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