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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"

32532 results found.

  1. GRB010324, optical observations
  2. Duration, ECT, peak flux and fluence of GRB010324
  3. Optical Observations of GRB 010324
  4. IPN TRIANGULATION OF GRB010324
  5. GRB990705, VLT-FORS1 observations of the host galaxy
  6. GRB010222, late-time optical observation
  7. GRB 010222 - HEGRA GeV/TeV Observations
  8. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  9. GRB010222: Chandra X-ray Observatory Observation
  10. GRB010222: Sub-millimeter vanishing act
  11. GRB010222 - Optical observation
  12. GRB 010222, Optical Observations
  13. GRB010220 optical obsercations
  14. GRB010222 - Optical observation
  15. GRB 010222: High-Resolution Keck Spectroscopy
  16. GRB010222: Optical observation and decay
  17. GRB 010214, I-band data
  18. Sub-millimeter Excess/GRB 010222
  19. GRB 010222
  20. GRB 010222 HST/Chandra TOO
  21. GRB010222 further R-band photometry
  22. GRB010222: R-band data
  23. GRB010222 Optical observations
  24. GRB 010222: Keck Spectroscopy
  25. GRB010222 further R-band photometry
  26. GRB010222, possible increase of optical decay slope
  27. GRB010222: fading behavior
  28. GRB 010222 BV optical observations
  29. GRB010222 R-BAND OBSERVATION
  30. GRB 010220: Near-IR Observations
  31. GRB010214 follow-up from Hanle
  32. GRB 010222: Near-IR Observations
  33. GRB 010222: Optical Observations
  34. GRB 010222, Decay Slope Confirmed
  35. GRB010222: Another absorption line system
  36. GRB010222: Optical decay slope
  37. GRB 010214, Optical Observations
  38. GRB010222: Sub-millimeter detection
  39. GRB010222: R-band fading behavior
  40. GRB010222: Optical Observations
  41. GRB010222, radio observations
  42. GRB010222, optical observations
  43. GRB010222: BeppoSAX/NFI Observations
  44. Redshift of the Optical Transient of GRB010222
  45. GRB010222: possible optical counterpart
  46. GRB010222
  47. GRB010222: BeppoSAX refined position
  48. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  49. GRB010220, Radio and Optical Observations
  50. GRB 010220, simultaneous optical observations
  51. GRB010220: BeppoSAX WFC and GRBM preliminary data
  52. GRB010214, candidate optical afterglow
  53. GRB010214, optical observations
  54. GRB010214: BeppoSAX WFC and GRBM preliminary data
  55. GRB 010214: X-Ray afterglow
  56. GRB 010214, Optical Observations
  57. GRB 010214 optical observation
  58. GRB010213, Radio Observations
  59. GRB010213 Optical Observation
  60. GRB010213, Radio Observations
  61. J-Band Observation of GRB 010214.
  62. GRB010214, Radio Observations
  63. GRB010214, optical observations
  64. GRB010213, optical observations
  65. Possible InfraRed Transient of GRB 010214.
  66. GRB010214 Optical Observation
  67. GRB010213 (HETE) TAROT observations
  68. GRB 010214, optical observations
  69. IPN Status Report
  70. HETE Status
  71. GRB010126 opt. obs.
  72. IPN/RXTE TRIANGULATION OF GRB010126
  73. GRB010126: CONCAM crude optical limits during GRB
  74. GRB010126, TNG R-band observations
  75. GRB010126 Optical Observations
  76. GRB010126 optical observations
  77. GRB010126: Optical observations
  78. IPN/RXTE TRIANGULATION OF GRB010126
  79. GRB 010119, optical observations
  80. GRB010119: Optical observations
  81. Optical Observations of GRB 001018 at Keck
  82. GRB010119, Radio observations
  83. Optical observations of GRB 001018 with JCAM
  84. IPN TRIANGULATION OF GRB010109
  85. GRB 001204: Ks observations
  86. H band observation of GRB 001212
  87. GRB 001212 Optical Observation
  88. GRB 001212 Optical Observation
  89. GRB 001212 optical observation
  90. GRB 001212 possible OA in 2MASS
  91. GRB 001212 possible OA
  92. GRB001204: Optical observations
  93. Confirmation of IPN position for GRB001204
  94. GRB001204, Radio observations
  95. GRB 001105, further optical observations
  96. GRB001120: Gunn-i observations
  97. GRB001109, optical observations
  98. WSRT 4.8 GHz observations of GRB001109
  99. Optical/NIR observations of GRB001109
  100. GRB 001109: deep JHK upper limits

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