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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"

27320 results found.

  1. GRB010222: Chandra X-ray Observatory Observation
  2. GRB010222: Sub-millimeter vanishing act
  3. GRB010222 - Optical observation
  4. GRB 010222, Optical Observations
  5. GRB010222 - Optical observation
  6. GRB 010222: High-Resolution Keck Spectroscopy
  7. GRB 010214, I-band data
  8. GRB 010222
  9. GRB010222 further R-band photometry
  10. GRB010222: R-band data
  11. GRB 010222: Keck Spectroscopy
  12. GRB010214, field photometry
  13. GRB010222, field photometry
  14. GRB010222 further R-band photometry
  15. GRB010222, possible increase of optical decay slope
  16. GRB 010222 Kyoto optical observation
  17. GRB010222 R-BAND OBSERVATION
  18. GRB010214 follow-up from Hanle
  19. GRB 010222: Near-IR Observations
  20. GRB 010222: Optical Observations
  21. GRB010222: Optical decay slope
  22. GRB 010214, Optical Observations
  23. GRB010222, radio observations
  24. GRB010222, optical observations
  25. GRB010222: BeppoSAX/NFI Observations
  26. GRB010214B,Gamma Ray Observations
  27. GRB 010220, simultaneous optical observations
  28. GRB010220: BeppoSAX WFC and GRBM preliminary data
  29. GRB010214, candidate optical afterglow
  30. GRB010214, optical observations
  31. GRB010214: BeppoSAX WFC and GRBM preliminary data
  32. GRB 010214: X-Ray afterglow
  33. GRB 010214 optical observation
  34. GRB010213, Radio Observations
  35. J-Band Observation of GRB 010214.
  36. GRB010213, Near-IR observations
  37. Possible InfraRed Transient of GRB 010214.
  38. GRB 010214, optical observations
  39. GRB010213 detected by HETE
  40. IPN Status Report
  41. HETE Status
  42. IPN/RXTE TRIANGULATION OF GRB010126
  43. GRB010126 Optical Observations
  44. IPN TRIANGULATION OF GRB010126
  45. Optical Observations of GRB 001018 at Keck
  46. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  47. Optical observations of GRB 001018 with JCAM
  48. IPN TRIANGULATION OF GRB010115
  49. IPN TRIANGULATION OF GRB010109
  50. IPN TRIANGULATION OF GRB010109
  51. IPN triangulation of GRB010104
  52. IPN triangulation of GRB010103
  53. H band observation of GRB 001212
  54. IPN triangulation of GRB001219
  55. GRB 001212 Optical Observation
  56. GRB 001212 Optical Observation
  57. GRB 001212 possible OA in 2MASS
  58. IPN triangulation of GRB001212
  59. Confirmation of IPN position for GRB001204
  60. IPN triangulation of GRB001204 (short/hard)
  61. GRB001120, optical observations
  62. WSRT 4.8 GHz observations of GRB001109
  63. IPN triangulation of GRB001120
  64. GRB 001109: deep JHK upper limits
  65. GRB 001109 X-ray afterglow with BeppoSAX
  66. CORRECTION to XMM-Newton observation of GRB001025
  67. GRB001109, Radio observations
  68. GRB001105 BVRI field photometry correction
  69. GRB001105, BVRI field photometry
  70. IPN TRIANGULATION OF GRB001105
  71. GRB 001025B, Optical obervations
  72. GRB 991208: HST Imaging of the Host Galaxy
  73. GRB 001025B, I-band observations
  74. XMM-Newton observation of GRB001025
  75. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  76. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  77. GRB001007: Optical observations
  78. ASM Localization of GRB 001025
  79. GRB001007, Radio observations
  80. GRB 001018, Possible Radio Afterglow
  81. GRB001018, Gamma Ray Observations
  82. IPN TRIANGULATION OF GRB001019
  83. IPN TRIANGULATION OF GRB001018
  84. IPN TRIANGULATION OF GRB 001017
  85. V,R,I band observations of GRB000926
  86. HETE positions added to GCN
  87. GRB000926 - Amateur Optical Observations
  88. CONCAM null result on GRB001005
  89. IPN triangulation of GRB001005
  90. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  91. GRB000926 - Optical observations
  92. GRB000926 - Optical observations
  93. GRB 000926, Optical Decay
  94. GRB000911: VLT infrared observation
  95. GRB 000926, Optical Observations
  96. GRB000926 K'-band Observation
  97. J and K band observations of GRB 000926
  98. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  99. CONCAM crude optical limits before and after GRB000926
  100. GRB 000926: Preliminary R-band Lightcurve

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