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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"

21264 results found.

  1. GRB010222, field photometry
  2. GRB010222 further R-band photometry
  3. GRB 010222 Kyoto optical observation
  4. GRB010222 R-BAND OBSERVATION
  5. GRB010214 follow-up from Hanle
  6. GRB 010222: Near-IR Observations
  7. GRB 010222: Optical Observations
  8. GRB010222, radio observations
  9. GRB010222, optical observations
  10. GRB010214B,Gamma Ray Observations
  11. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  12. GRB 010220, simultaneous optical observations
  13. GRB010220: BeppoSAX WFC and GRBM preliminary data
  14. GRB010214, optical observations
  15. GRB010214: BeppoSAX WFC and GRBM preliminary data
  16. GRB 010214: X-Ray afterglow
  17. GRB 010214 optical observation
  18. GRB010213, Radio Observations
  19. J-Band Observation of GRB 010214.
  20. GRB010214, Radio Observations
  21. GRB010213, Near-IR observations
  22. Possible InfraRed Transient of GRB 010214.
  23. GRB010213 (HETE) TAROT observations
  24. GRB010213 detected by HETE
  25. BeppoSAX ALERT: GRB010214
  26. HETE Status
  27. IPN/RXTE TRIANGULATION OF GRB010126
  28. GRB010126 optical observations
  29. IPN/RXTE TRIANGULATION OF GRB010126
  30. Optical Observations of GRB 001018 at Keck
  31. GRB010119, Radio observations
  32. Optical observations of GRB 001018 with JCAM
  33. IPN TRIANGULATION OF GRB010115
  34. IPN TRIANGULATION OF GRB010109
  35. IPN triangulation of GRB010103
  36. GRB 001204: Ks observations
  37. GRB 001212 Optical Observation
  38. GRB 001212 Optical Observation
  39. GRB001204, Radio observations
  40. IPN triangulation of GRB001204 (short/hard)
  41. GRB001120: Gunn-i observations
  42. GRB001120, optical observations
  43. WSRT 4.8 GHz observations of GRB001109
  44. IPN triangulation of GRB001120
  45. GRB 001109: deep JHK upper limits
  46. GRB 001109 X-ray afterglow with BeppoSAX
  47. CORRECTION to XMM-Newton observation of GRB001025
  48. GRB001109, Radio observations
  49. GRB001105 BVRI field photometry correction
  50. GRB001105, BVRI field photometry
  51. GRB 001025B, Optical obervations
  52. GRB 991208: HST Imaging of the Host Galaxy
  53. GRB 001025B, I-band observations
  54. GRB001025B, Radio observations
  55. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  56. IPN triangulation of GRB001025
  57. GRB001007: Optical observations
  58. ASM Localization of GRB 001025
  59. GRB001007, Radio observations
  60. IPN TRIANGULATION OF GRB001020
  61. GRB001018, Gamma Ray Observations
  62. V,R,I band observations of GRB000926
  63. The Likely Optical/Infrared Afterglow of GRB 001011
  64. HETE positions added to GCN
  65. BeppoSAX ALERT: GRB001011
  66. GRB000926 - Amateur Optical Observations
  67. CONCAM null result on GRB001005
  68. IPN triangulation of GRB001007
  69. IPN triangulation of GRB001005
  70. GRB 000926 Chandra Observation
  71. IPN triangulation of GRB 001004
  72. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  73. GRB000926 - Optical observations
  74. GRB000926 - Optical observations
  75. GRB 000926, Optical Observations
  76. GRB000926 K'-band Observation
  77. J and K band observations of GRB 000926
  78. GRB 000926, optical observation by Oksanen (vsnet-grb)
  79. CONCAM crude optical limits before and after GRB000926
  80. Spectroscopic Redshift of GRB 000926
  81. GRB 000926: Optical candidate
  82. Optical candidate for GRB000926
  83. IPN triangulation of GRB000926
  84. GRB 000911, BVRI field photometry
  85. IPN triangulation of GRB000925
  86. GRB000911: Optical Transient
  87. GRB000911, Radio and Optical observations
  88. GRB000911: Optical observations
  89. IPN triangulation of GRB000911
  90. GRB000830, BVRI field photometry
  91. Chandra Position of GRB000210
  92. IPN localization of GRB000820
  93. SGR 1806-20 burst activity
  94. GRB000730, Gamma Ray Observations
  95. IPN localization of GRB000812
  96. IPN localization of GRB000811
  97. GRB000801, Gamma Ray Observations
  98. GRB000801, VLT-Antu R-band observations
  99. GRB 991208 Host Galaxy Imaging
  100. IPN localization of GRB000801

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