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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"

17409 results found.

  1. GRB 010326 optical observations
  2. GRB010326: Refined Localization by HETE
  3. GRB010326: Localization by HETE
  4. Optical Observations of GRB 010324
  5. IPN TRIANGULATION OF GRB010324
  6. GRB010222, late-time optical observation
  7. Support extension to the BeppoSAX mission
  8. GRB 010222, Optical Observations
  9. GRB010220 optical obsercations
  10. GRB010222 - Optical observation
  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. GRB 010222, Decay Slope Confirmed
  22. GRB010222, radio observations
  23. GRB010222, optical observations
  24. GRB 010220, simultaneous optical observations
  25. GRB010220: BeppoSAX WFC and GRBM preliminary data
  26. GRB010214, optical observations
  27. GRB010214: BeppoSAX WFC and GRBM preliminary data
  28. GRB 010214: X-Ray afterglow
  29. GRB 010214 optical observation
  30. J-Band Observation of GRB 010214.
  31. GRB010214, optical observations
  32. GRB010213, optical observations
  33. GRB010213, Near-IR observations
  34. Possible InfraRed Transient of GRB 010214.
  35. GRB010214 Optical Observation
  36. GRB010213 detected by HETE
  37. HETE Status
  38. Optical Observations of GRB 001018 at Keck
  39. Optical observations of GRB 001018 with JCAM
  40. IPN TRIANGULATION OF GRB010109
  41. IPN triangulation of GRB010104
  42. IPN triangulation of GRB010103
  43. IPN triangulation of GRB001219
  44. GRB 001212 Optical Observation
  45. GRB 001212 Optical Observation
  46. GRB001120, optical observations
  47. GRB 001109: deep JHK upper limits
  48. GRB 001109 X-ray afterglow with BeppoSAX
  49. CORRECTION to XMM-Newton observation of GRB001025
  50. GRB001109, Radio observations
  51. GRB001105 BVRI field photometry correction
  52. GRB001105, BVRI field photometry
  53. GRB 001025B, Optical obervations
  54. GRB 991208: HST Imaging of the Host Galaxy
  55. GRB 001025B, I-band observations
  56. GRB 001025A, optical observation
  57. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  58. GRB001007: Optical observations
  59. GRB001007, Radio observations
  60. IPN TRIANGULATION OF GRB001020
  61. CORRECTION TO PEAK FLUX OF GRB001018
  62. IPN TRIANGULATION OF GRB 001017
  63. V,R,I band observations of GRB000926
  64. GRB000926 - Amateur Optical Observations
  65. CONCAM null result on GRB001005
  66. GRB000926 - Optical observations
  67. GRB000926 - Optical observations
  68. GRB 000926, Optical Observations
  69. GRB000926 K'-band Observation
  70. J and K band observations of GRB 000926
  71. CONCAM crude optical limits before and after GRB000926
  72. GRB 000926: Optical candidate
  73. Optical candidate for GRB000926
  74. GRB 000911, BVRI field photometry
  75. GRB000911, Radio and Optical observations
  76. GRB000911: Optical observations
  77. False GRB alarm from RXTE/ASM on 8 Sept 2000
  78. GRB000830, BVRI field photometry
  79. GRB000830: Optical observations
  80. IPN localization of GRB000820
  81. IPN localization of GRB000812
  82. GRB000801, VLT-Antu R-band observations
  83. GRB 991208 Host Galaxy Imaging
  84. IPN localization of GRB000730B
  85. IPN localization of GRB000730B
  86. GRB 990510: Possible detection of a host galaxy
  87. GRB 990510 Host Galaxy Discovery
  88. GRB 990712: Late time HST/STIS Observations
  89. GRB 991216, HST/STIS observations
  90. GRB000630, optical observations
  91. GRB000630, Revised BVRI Field Photometry
  92. GRB000630, Optical Observations
  93. GRB000630, optical observations
  94. GRB000630, optical observations
  95. GRB000630, BVRI Field Photometry
  96. GRB000630, optical observations
  97. GRB000630, optical observations
  98. GRB000630: Optical observations
  99. possible optical counterpart of GRB 000630
  100. IPN triangulation of GRB000630

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