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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"

32507 results found.

  1. GRB010222, possible increase of optical decay slope
  2. GRB010222: fading behavior
  3. GRB 010222 BV optical observations
  4. GRB010222 R-BAND OBSERVATION
  5. GRB 010220: Near-IR Observations
  6. GRB010214 follow-up from Hanle
  7. GRB 010222: Near-IR Observations
  8. GRB 010222: Optical Observations
  9. GRB 010222, Decay Slope Confirmed
  10. GRB010222: Another absorption line system
  11. GRB010222: Optical decay slope
  12. GRB 010214, Optical Observations
  13. GRB010222: Sub-millimeter detection
  14. GRB010222: R-band fading behavior
  15. GRB010222: Optical Observations
  16. GRB010222, radio observations
  17. GRB010222, optical observations
  18. GRB010222: BeppoSAX/NFI Observations
  19. Redshift of the Optical Transient of GRB010222
  20. GRB010222: possible optical counterpart
  21. GRB010222
  22. GRB010222: BeppoSAX refined position
  23. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  24. GRB010220, Radio and Optical Observations
  25. GRB 010220, simultaneous optical observations
  26. GRB010220: BeppoSAX WFC and GRBM preliminary data
  27. GRB010214, candidate optical afterglow
  28. GRB010214, optical observations
  29. GRB010214: BeppoSAX WFC and GRBM preliminary data
  30. GRB 010214: X-Ray afterglow
  31. GRB 010214, Optical Observations
  32. GRB 010214 optical observation
  33. GRB010213, Radio Observations
  34. GRB010213 Optical Observation
  35. GRB010213, Radio Observations
  36. J-Band Observation of GRB 010214.
  37. GRB010214, Radio Observations
  38. GRB010214, optical observations
  39. GRB010213, optical observations
  40. Possible InfraRed Transient of GRB 010214.
  41. GRB010214 Optical Observation
  42. GRB010213 (HETE) TAROT observations
  43. GRB 010214, optical observations
  44. IPN Status Report
  45. HETE Status
  46. GRB010126 opt. obs.
  47. IPN/RXTE TRIANGULATION OF GRB010126
  48. GRB010126: CONCAM crude optical limits during GRB
  49. GRB010126, TNG R-band observations
  50. GRB010126 Optical Observations
  51. GRB010126 optical observations
  52. GRB010126: Optical observations
  53. IPN/RXTE TRIANGULATION OF GRB010126
  54. GRB 010119, optical observations
  55. GRB010119: Optical observations
  56. Optical Observations of GRB 001018 at Keck
  57. GRB010119, Radio observations
  58. Optical observations of GRB 001018 with JCAM
  59. IPN TRIANGULATION OF GRB010109
  60. GRB 001204: Ks observations
  61. H band observation of GRB 001212
  62. GRB 001212 Optical Observation
  63. GRB 001212 Optical Observation
  64. GRB 001212 optical observation
  65. GRB 001212 possible OA in 2MASS
  66. GRB 001212 possible OA
  67. GRB001204: Optical observations
  68. Confirmation of IPN position for GRB001204
  69. GRB001204, Radio observations
  70. GRB 001105, further optical observations
  71. GRB001120: Gunn-i observations
  72. GRB001109, optical observations
  73. WSRT 4.8 GHz observations of GRB001109
  74. Optical/NIR observations of GRB001109
  75. GRB 001109: deep JHK upper limits
  76. GRB 001109 X-ray afterglow with BeppoSAX
  77. CORRECTION to XMM-Newton observation of GRB001025
  78. GRB001109: Optical observations
  79. GRB001109, R-band optical observations
  80. GRB001109, Radio observations
  81. GRB001105 BVRI field photometry correction
  82. GRB001105, BVRI field photometry
  83. GRB 001105, R-band observation
  84. GRB 991208: HST Imaging of the Host Galaxy
  85. GRB000926: R-image of the host galaxy
  86. GRB 001025B, I-band observations
  87. XMM-Newton observation of GRB001025
  88. GRB001025B, Radio observations
  89. GRB 001025 Optical Observations
  90. GRB 001025A, optical observation
  91. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  92. IPN triangulation of GRB001025
  93. GRB001007: Optical observations
  94. GRB001007, Radio observations
  95. GRB 001018, Possible Radio Afterglow
  96. CORRECTION TO PEAK FLUX OF GRB001018
  97. GRB 000926: Improved Absorber Redshift
  98. V,R,I band observations of GRB000926
  99. The Likely Optical/Infrared Afterglow of GRB 001011
  100. HETE positions added to GCN

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