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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"

20388 results found.

  1. SGR 1900+14, Chandra observations
  2. Chandra Observations of SGR 1900+14
  3. SGR1900+14, I-band observations
  4. IPN Triangulation of the Giant Flare from SGR1900+14
  5. GRB010412, field photometry
  6. Giant flare from SGR1900+14
  7. GRB 010326b Optical Observations
  8. GRB010412: BeppoSAX GRBM and WFC observations
  9. GRB010324, revised field photometry
  10. GRB 980326: Late-time HST/STIS observations
  11. GRB010324, field photometry
  12. GRB010326B, field photometry
  13. GRB010326, field photometry
  14. GRB010220, field photometry
  15. Further Optical Observations of GRB 010324
  16. GRB010222, CXO X-ray observations
  17. GRB010324, optical observations
  18. GRB010326B: Localization by HETE (2nd GRB for this date)
  19. GRB 010326 optical observations
  20. GRB010326: Refined Localization by HETE
  21. GRB010326: Localization by HETE
  22. Optical Observations of GRB 010324
  23. GRB010222, late-time optical observation
  24. Support extension to the BeppoSAX mission
  25. GRB 010222 - HEGRA GeV/TeV Observations
  26. GRB010222 - Optical observation
  27. GRB 010222, Optical Observations
  28. GRB 010214, I-band data
  29. GRB010222 further R-band photometry
  30. GRB 010222: Keck Spectroscopy
  31. GRB010214, field photometry
  32. GRB010222, field photometry
  33. GRB010222 further R-band photometry
  34. GRB010222, possible increase of optical decay slope
  35. GRB 010222 Kyoto optical observation
  36. GRB 010222 BV optical observations
  37. GRB010222 R-BAND OBSERVATION
  38. GRB010214 follow-up from Hanle
  39. GRB 010222: Near-IR Observations
  40. GRB 010222: Optical Observations
  41. GRB010222, radio observations
  42. GRB010222, optical observations
  43. GRB010220, Radio and Optical Observations
  44. GRB 010220, simultaneous optical observations
  45. GRB010220: BeppoSAX WFC and GRBM preliminary data
  46. GRB010214, optical observations
  47. BeppoSAX GRB010220: refined position
  48. GRB010214: BeppoSAX WFC and GRBM preliminary data
  49. GRB 010214: X-Ray afterglow
  50. GRB 010214 optical observation
  51. J-Band Observation of GRB 010214.
  52. GRB010213, Near-IR observations
  53. Possible InfraRed Transient of GRB 010214.
  54. GRB010213 (HETE) TAROT observations
  55. GRB010213 detected by HETE
  56. IPN Status Report
  57. HETE Status
  58. GRB010126 Optical Observations
  59. IPN TRIANGULATION OF GRB010126
  60. Optical Observations of GRB 001018 at Keck
  61. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  62. Optical observations of GRB 001018 with JCAM
  63. IPN TRIANGULATION OF GRB010115
  64. IPN TRIANGULATION OF GRB010109
  65. IPN TRIANGULATION OF GRB010109
  66. IPN triangulation of GRB010104
  67. IPN triangulation of GRB010103
  68. IPN triangulation of GRB001219
  69. GRB 001212 Optical Observation
  70. GRB 001212 Optical Observation
  71. GRB 001212 possible OA
  72. IPN triangulation of GRB001212
  73. Confirmation of IPN position for GRB001204
  74. IPN triangulation of GRB001204 (short/hard)
  75. GRB001120, optical observations
  76. WSRT 4.8 GHz observations of GRB001109
  77. IPN triangulation of GRB001120
  78. GRB 001109: deep JHK upper limits
  79. GRB 001109 X-ray afterglow with BeppoSAX
  80. CORRECTION to XMM-Newton observation of GRB001025
  81. GRB001109, Radio observations
  82. BeppoSAX ALERT: GRB001109
  83. GRB001105 BVRI field photometry correction
  84. GRB001105, BVRI field photometry
  85. IPN TRIANGULATION OF GRB001105
  86. GRB 001025B, Optical obervations
  87. GRB 991208: HST Imaging of the Host Galaxy
  88. GRB 001025B, I-band observations
  89. XMM-Newton observation of GRB001025
  90. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  91. GRB001007: Optical observations
  92. ASM Localization of GRB 001025
  93. GRB001007, Radio observations
  94. IPN TRIANGULATION OF GRB001019
  95. IPN TRIANGULATION OF GRB001018
  96. IPN TRIANGULATION OF GRB 001017
  97. V,R,I band observations of GRB000926
  98. HETE positions added to GCN
  99. GRB 001007, BVR-band observations
  100. GRB000926 - Amateur Optical Observations

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