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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"

21770 results found.

  1. Support extension to the BeppoSAX mission
  2. GRB 010222, Optical Observations
  3. GRB 010222: High-Resolution Keck Spectroscopy
  4. GRB010222 further R-band photometry
  5. GRB 010222: Keck Spectroscopy
  6. GRB010214, field photometry
  7. GRB010222, field photometry
  8. GRB010222 further R-band photometry
  9. GRB 010222 Kyoto optical observation
  10. GRB010222 R-BAND OBSERVATION
  11. GRB010214 follow-up from Hanle
  12. GRB 010222: Near-IR Observations
  13. GRB 010222: Optical Observations
  14. GRB010222, radio observations
  15. GRB010222, optical observations
  16. GRB010214B,Gamma Ray Observations
  17. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  18. GRB 010220, simultaneous optical observations
  19. GRB010220: BeppoSAX WFC and GRBM preliminary data
  20. GRB010214, optical observations
  21. GRB010214: BeppoSAX WFC and GRBM preliminary data
  22. GRB 010214: X-Ray afterglow
  23. GRB 010214 optical observation
  24. GRB010213, Radio Observations
  25. J-Band Observation of GRB 010214.
  26. GRB010214, Radio Observations
  27. GRB010213, Near-IR observations
  28. Possible InfraRed Transient of GRB 010214.
  29. GRB010213 (HETE) TAROT observations
  30. GRB010213 detected by HETE
  31. BeppoSAX ALERT: GRB010214
  32. HETE Status
  33. IPN/RXTE TRIANGULATION OF GRB010126
  34. GRB010126 optical observations
  35. IPN/RXTE TRIANGULATION OF GRB010126
  36. Optical Observations of GRB 001018 at Keck
  37. GRB010119, Radio observations
  38. Optical observations of GRB 001018 with JCAM
  39. IPN TRIANGULATION OF GRB010115
  40. IPN TRIANGULATION OF GRB010109
  41. IPN triangulation of GRB010103
  42. GRB 001204: Ks observations
  43. GRB 001212 Optical Observation
  44. GRB 001212 Optical Observation
  45. GRB001204, Radio observations
  46. IPN triangulation of GRB001204 (short/hard)
  47. GRB001120: Gunn-i observations
  48. GRB001120, optical observations
  49. WSRT 4.8 GHz observations of GRB001109
  50. IPN triangulation of GRB001120
  51. GRB 001109: deep JHK upper limits
  52. GRB 001109 X-ray afterglow with BeppoSAX
  53. CORRECTION to XMM-Newton observation of GRB001025
  54. GRB001109, Radio observations
  55. GRB001105 BVRI field photometry correction
  56. GRB001105, BVRI field photometry
  57. GRB 001025B, Optical obervations
  58. GRB 991208: HST Imaging of the Host Galaxy
  59. GRB 001025B, I-band observations
  60. GRB001025B, Radio observations
  61. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  62. IPN triangulation of GRB001025
  63. GRB001007: Optical observations
  64. ASM Localization of GRB 001025
  65. GRB001007, Radio observations
  66. IPN TRIANGULATION OF GRB001020
  67. GRB001018, Gamma Ray Observations
  68. V,R,I band observations of GRB000926
  69. The Likely Optical/Infrared Afterglow of GRB 001011
  70. HETE positions added to GCN
  71. BeppoSAX ALERT: GRB001011
  72. GRB000926 - Amateur Optical Observations
  73. CONCAM null result on GRB001005
  74. IPN triangulation of GRB001007
  75. IPN triangulation of GRB001005
  76. GRB 000926 Chandra Observation
  77. IPN triangulation of GRB 001004
  78. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  79. GRB000926 - Optical observations
  80. GRB000926 - Optical observations
  81. GRB 000926, Optical Observations
  82. GRB000926 K'-band Observation
  83. J and K band observations of GRB 000926
  84. GRB 000926, optical observation by Oksanen (vsnet-grb)
  85. CONCAM crude optical limits before and after GRB000926
  86. Spectroscopic Redshift of GRB 000926
  87. GRB 000926: Optical candidate
  88. Optical candidate for GRB000926
  89. IPN triangulation of GRB000926
  90. GRB 000911, BVRI field photometry
  91. IPN triangulation of GRB000925
  92. GRB000911: Optical Transient
  93. GRB000911, Radio and Optical observations
  94. GRB000911: Optical observations
  95. IPN triangulation of GRB000911
  96. GRB000830, BVRI field photometry
  97. Chandra Position of GRB000210
  98. IPN localization of GRB000820
  99. SGR 1806-20 burst activity
  100. GRB000730, Gamma Ray Observations

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