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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"

20377 results found.

  1. GRB010324, optical observations
  2. GRB010326B: Localization by HETE (2nd GRB for this date)
  3. GRB 010326 optical observations
  4. GRB010326: Refined Localization by HETE
  5. GRB010326: Localization by HETE
  6. Optical Observations of GRB 010324
  7. GRB010222, late-time optical observation
  8. Support extension to the BeppoSAX mission
  9. GRB 010222, Optical Observations
  10. GRB 010222: High-Resolution Keck Spectroscopy
  11. GRB010222 further R-band photometry
  12. GRB 010222: Keck Spectroscopy
  13. GRB010214, field photometry
  14. GRB010222, field photometry
  15. GRB010222 further R-band photometry
  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, radio observations
  22. GRB010222, optical observations
  23. GRB010214B,Gamma Ray Observations
  24. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  25. GRB 010220, simultaneous optical observations
  26. GRB010220: BeppoSAX WFC and GRBM preliminary data
  27. GRB010214, optical observations
  28. GRB010214: BeppoSAX WFC and GRBM preliminary data
  29. GRB 010214: X-Ray afterglow
  30. GRB 010214 optical observation
  31. GRB010213, Radio Observations
  32. J-Band Observation of GRB 010214.
  33. GRB010214, Radio Observations
  34. GRB010213, Near-IR observations
  35. Possible InfraRed Transient of GRB 010214.
  36. GRB010213 (HETE) TAROT observations
  37. GRB010213 detected by HETE
  38. BeppoSAX ALERT: GRB010214
  39. HETE Status
  40. IPN/RXTE TRIANGULATION OF GRB010126
  41. GRB010126 optical observations
  42. IPN/RXTE TRIANGULATION OF GRB010126
  43. Optical Observations of GRB 001018 at Keck
  44. GRB010119, Radio observations
  45. Optical observations of GRB 001018 with JCAM
  46. IPN TRIANGULATION OF GRB010115
  47. IPN TRIANGULATION OF GRB010109
  48. IPN triangulation of GRB010103
  49. GRB 001204: Ks observations
  50. GRB 001212 Optical Observation
  51. GRB 001212 Optical Observation
  52. GRB001204, Radio observations
  53. IPN triangulation of GRB001204 (short/hard)
  54. GRB001120: Gunn-i observations
  55. GRB001120, optical observations
  56. WSRT 4.8 GHz observations of GRB001109
  57. IPN triangulation of GRB001120
  58. GRB 001109: deep JHK upper limits
  59. GRB 001109 X-ray afterglow with BeppoSAX
  60. CORRECTION to XMM-Newton observation of GRB001025
  61. GRB001109, Radio observations
  62. GRB001105 BVRI field photometry correction
  63. GRB001105, BVRI field photometry
  64. GRB 001025B, Optical obervations
  65. GRB 991208: HST Imaging of the Host Galaxy
  66. GRB 001025B, I-band observations
  67. GRB001025B, Radio observations
  68. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  69. IPN triangulation of GRB001025
  70. GRB001007: Optical observations
  71. ASM Localization of GRB 001025
  72. GRB001007, Radio observations
  73. IPN TRIANGULATION OF GRB001020
  74. GRB001018, Gamma Ray Observations
  75. V,R,I band observations of GRB000926
  76. The Likely Optical/Infrared Afterglow of GRB 001011
  77. HETE positions added to GCN
  78. BeppoSAX ALERT: GRB001011
  79. GRB000926 - Amateur Optical Observations
  80. CONCAM null result on GRB001005
  81. IPN triangulation of GRB001007
  82. IPN triangulation of GRB001005
  83. GRB 000926 Chandra Observation
  84. IPN triangulation of GRB 001004
  85. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  86. GRB000926 - Optical observations
  87. GRB000926 - Optical observations
  88. GRB 000926, Optical Observations
  89. GRB000926 K'-band Observation
  90. J and K band observations of GRB 000926
  91. GRB 000926, optical observation by Oksanen (vsnet-grb)
  92. CONCAM crude optical limits before and after GRB000926
  93. Spectroscopic Redshift of GRB 000926
  94. GRB 000926: Optical candidate
  95. Optical candidate for GRB000926
  96. IPN triangulation of GRB000926
  97. GRB 000911, BVRI field photometry
  98. IPN triangulation of GRB000925
  99. GRB000911: Optical Transient
  100. GRB000911, Radio and Optical observations

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