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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"

40752 results found.

  1. GRB010222, radio observations
  2. GRB010222, optical observations
  3. GRB010222: BeppoSAX/NFI Observations
  4. Redshift of the Optical Transient of GRB010222
  5. GRB010214B,Gamma Ray Observations
  6. GRB010222: possible optical counterpart
  7. GRB010222
  8. GRB010222: BeppoSAX refined position
  9. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  10. GRB010220, Radio and Optical Observations
  11. GRB 010220, simultaneous optical observations
  12. GRB010220: BeppoSAX WFC and GRBM preliminary data
  13. GRB010214, candidate optical afterglow
  14. GRB010214, optical observations
  15. GRB010214: BeppoSAX WFC and GRBM preliminary data
  16. GRB 010214: X-Ray afterglow
  17. GRB 010214, Optical Observations
  18. GRB 010214 optical observation
  19. GRB010213, Radio Observations
  20. GRB010213 Optical Observation
  21. GRB010213, Radio Observations
  22. J-Band Observation of GRB 010214.
  23. GRB010214, Radio Observations
  24. GRB010214, optical observations
  25. GRB010213, optical observations
  26. Possible InfraRed Transient of GRB 010214.
  27. GRB010214 Optical Observation
  28. GRB010214: BeppoSAX/NFI Observations
  29. GRB010213 (HETE) TAROT observations
  30. GRB 010214, optical observations
  31. GRB010213 detected by HETE
  32. IPN Status Report
  33. HETE Status
  34. GRB010126 opt. obs.
  35. IPN/RXTE TRIANGULATION OF GRB010126
  36. GRB010126: CONCAM crude optical limits during GRB
  37. GRB010126, TNG R-band observations
  38. GRB010126 Optical Observations
  39. GRB010126 optical observations
  40. GRB010126: Optical observations
  41. IPN/RXTE TRIANGULATION OF GRB010126
  42. GRB 010119, optical observations
  43. GRB010119: Optical observations
  44. Optical Observations of GRB 001018 at Keck
  45. GRB010119, Radio observations
  46. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  47. Optical observations of GRB 001018 with JCAM
  48. IPN TRIANGULATION OF GRB010109
  49. GRB 001204: Ks observations
  50. H band observation of GRB 001212
  51. GRB 001212 Optical Observation
  52. GRB 001212 Optical Observation
  53. GRB 001212 optical observation
  54. GRB 001212 possible OA in 2MASS
  55. GRB 001212 possible OA
  56. GRB001204: Optical observations
  57. Confirmation of IPN position for GRB001204
  58. GRB001204, Radio observations
  59. IPN triangulation of GRB001204 (short/hard)
  60. GRB 001105, further optical observations
  61. GRB001120: Gunn-i observations
  62. GRB001120: Optical observations
  63. GRB001109, optical observations
  64. GRB001120, optical observations
  65. WSRT 4.8 GHz observations of GRB001109
  66. Optical/NIR observations of GRB001109
  67. GRB 001109: deep JHK upper limits
  68. GRB 001109 X-ray afterglow with BeppoSAX
  69. CORRECTION to XMM-Newton observation of GRB001025
  70. GRB001109: Optical observations
  71. GRB001109: BeppoSAX/NFI Observations
  72. GRB001109, R-band optical observations
  73. GRB001109, Radio observations
  74. GRB001105 BVRI field photometry correction
  75. GRB001105, BVRI field photometry
  76. GRB 001105, R-band observation
  77. GRB 001025B, Optical obervations
  78. GRB 991208: HST Imaging of the Host Galaxy
  79. GRB000926: R-image of the host galaxy
  80. GRB 001025B, I-band observations
  81. XMM-Newton observation of GRB001025
  82. GRB001025B, Radio observations
  83. GRB 001025 Optical Observations
  84. GRB 001025A, optical observation
  85. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  86. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  87. IPN triangulation of GRB001025
  88. GRB001007: Optical observations
  89. ASM Localization of GRB 001025
  90. GRB001007, Radio observations
  91. GRB001019, Optical Observations
  92. GRB 001018, Possible Radio Afterglow
  93. GRB001018, Gamma Ray Observations
  94. CORRECTION TO PEAK FLUX OF GRB001018
  95. GRB 000926: Improved Absorber Redshift
  96. V,R,I band observations of GRB000926
  97. The Likely Optical/Infrared Afterglow of GRB 001011
  98. HETE positions added to GCN
  99. GRB001011 BeppoSAX/WFC refined position
  100. GRB 001007, BVR-band observations

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