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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"

32512 results found.

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

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