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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"

31734 results found.

  1. GRB090217: Fermi-LAT Detection
  2. SGR activity seen by BAT during ICSP Ionospheric Events
  3. Detailed lightcurves of ICSP VLF Observation of SGR/AXP 1E1547.0-5408
  4. VLA radio upper limit on GRB 090205
  5. GRB 090205: VLT optical decay
  6. GRB 090205: Swift/UVOT Upper Limits
  7. GRB 090205: VLT refined redshift
  8. GRB 090205: Swift-XRT refined analysis
  9. GRB 090205: VLT spectroscopic redshift
  10. GRB 090205: GROND observations and photometric redshift estimate
  11. GRB 090205: VLT candidate afterglow
  12. GRB 090205: Swift-BAT refined analysis
  13. GRB 080319B: IceCube upper limit on high-energy neutrino flux
  14. GRB 090131: Suzaku WAM observation of the prompt emission
  15. ICSP VLF observation of the signatures of SGR/AXP 1E1547.0-5408 bursts
  16. GRB 090126A: Swift-XRT afterglow confirmation
  17. Konus-Wind observation of GRB 090201
  18. GRB 090201: Swift-XRT refined analysis
  19. GRB090201: Swift UVOT upper limits
  20. GRB 090201: object inside the enhanced XRT error circle
  21. GRB 090201: VLT NIR observations
  22. GRB 090201: Swift-BAT refined analysis
  23. GRB 090201: VLT afterglow candidate
  24. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  25. GRB090113: MAGIC telescope GeV observation
  26. GRB 090201: ROTSE-III Optical Limits
  27. GRB 090126A: Swift/UVOT Upper Limits
  28. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  29. GRB 090129: Swift-BAT refined analysis
  30. Suzaku ToO Observation of AXP 1E 1547.0-5408
  31. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  32. AXP 1E1547.0-5408: RHESSI observations up to 400 keV
  33. GRB 090102: HST observations and host galaxy
  34. GRB 090126A: Swift-XRT Refined Analysis
  35. GRB 090118: no afterglow candidate
  36. GRB 090123: GROND detection
  37. 1E1547.0-5408: Swift detection of dust halo
  38. GRB 090123: Swift XRT refined analysis
  39. GRB 090123: Swift/UVOT Observations
  40. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity
  41. GRB 090123: Swift-BAT refined analysis
  42. AXP 1E1547.0-5408: long bursts with INTEGRAL SPI-ACS
  43. GRB 090118: Swift XRT Observations - Confirmation of an Afterglow
  44. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  45. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  46. AXP 1E1547.0-5408: Fermi GBM observations
  47. Trigger 340734: Swift detection of a possible short burst
  48. GRB 090118: Subaru NIR Observation
  49. GRB 090118: KPNO 4m 2nd Epoch Observations
  50. GRB 090118 (BATSS): GRT Optical Observation
  51. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  52. GRB 090118: Swift-XRT observations
  53. GRB090118 Swift/UVOT upper limits
  54. GRB 090118: GROND Upper Limits
  55. GRB 090117: confirmation of the X-ray afterglow
  56. GRB 090117 - Fermi GBM Observations
  57. GRB 090117: GROND Upper Limits
  58. GRB090117 Swift/UVOT upper limits
  59. GRB 090112B: Suzaku WAM observation of the prompt emission
  60. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  61. GRB 090113: Swift UVOT upper limits
  62. GRB 090113: GROND Upper Limits
  63. GRB 090113: Swift-XRT refined analysis
  64. GRB 090113: Observations from NOT
  65. GRB 090113: Swift-BAT refined analysis
  66. GRB 090113: ROTSE-III Optical Limits
  67. GRB090113: XRT position
  68. GRB 090111, Swift-BAT refined analysis
  69. GRB 090111: Swift UVOT Upper Limits
  70. GRB 090111: Swift-XRT refined analysis
  71. GRB 090107B: Suzaku WAM observation of the prompt emission
  72. GRB090107B: Fermi GBM Detection
  73. GRB 090102: WSRT Radio Observations
  74. GRB 090107B: Swift XRT afterglow confirmation
  75. GRB 090107B: Swift/UVOT Observations
  76. GRB 090107B: Swift-XRT detection of possible afterglow
  77. GRB 090107B optical observations
  78. GRB 090107B: ROTSE-III Optical Limits
  79. Fermi/GBM detection of GRB 081226A
  80. GRB 090107: Swift-BAT refined analysis
  81. GRB 090102: optical decay
  82. VLA radio upper limit on GRB 090102
  83. GRB 090102: GRT Optical Observation
  84. Konus-Wind observation of GRB 090102
  85. GRB 090102: Hobby-Eberly Telescope Spectroscopy
  86. GRB 090102: P60 Imaging and P200 Spectroscopy
  87. GRB 090102 Observations from IAC80
  88. GRB 090102: GROND observations of the optical afterglow
  89. Swift UVOT observations of GRB 090102
  90. GRB 090102: Swift-BAT refined analysis
  91. GRB 090102: Swift XRT refined analysis
  92. GRB 090102: NOT redshift
  93. GRB 090102: TAROT Calern observatory optical light curve
  94. GRB 090102: REM observations of a bright afterglow
  95. GRB 081230: GROND confirmation of the afterglow
  96. GRB 081230, Swift-BAT refined analysis
  97. GRB081230: Swift-XRT refined analysis
  98. GRB 081230 Swift/UVOT Observations
  99. GRB 081230: Swift/UVOT Detection of an Optical Afterglow
  100. GRB 081230: ROTSE-III Detection of Optical Counterpart

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