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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"

27391 results found.

  1. GRB010214, optical observations
  2. GRB010214: BeppoSAX WFC and GRBM preliminary data
  3. GRB 010214: X-Ray afterglow
  4. GRB 010214 optical observation
  5. GRB010213, Radio Observations
  6. J-Band Observation of GRB 010214.
  7. GRB010213, Near-IR observations
  8. Possible InfraRed Transient of GRB 010214.
  9. GRB 010214, optical observations
  10. GRB010213 detected by HETE
  11. IPN Status Report
  12. HETE Status
  13. IPN/RXTE TRIANGULATION OF GRB010126
  14. GRB010126 Optical Observations
  15. IPN TRIANGULATION OF GRB010126
  16. Optical Observations of GRB 001018 at Keck
  17. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  18. Optical observations of GRB 001018 with JCAM
  19. IPN TRIANGULATION OF GRB010115
  20. IPN TRIANGULATION OF GRB010109
  21. IPN TRIANGULATION OF GRB010109
  22. IPN triangulation of GRB010104
  23. IPN triangulation of GRB010103
  24. H band observation of GRB 001212
  25. IPN triangulation of GRB001219
  26. GRB 001212 Optical Observation
  27. GRB 001212 Optical Observation
  28. GRB 001212 possible OA in 2MASS
  29. IPN triangulation of GRB001212
  30. Confirmation of IPN position for GRB001204
  31. IPN triangulation of GRB001204 (short/hard)
  32. GRB001120, optical observations
  33. WSRT 4.8 GHz observations of GRB001109
  34. IPN triangulation of GRB001120
  35. GRB 001109: deep JHK upper limits
  36. GRB 001109 X-ray afterglow with BeppoSAX
  37. CORRECTION to XMM-Newton observation of GRB001025
  38. GRB001109, Radio observations
  39. GRB001105 BVRI field photometry correction
  40. GRB001105, BVRI field photometry
  41. IPN TRIANGULATION OF GRB001105
  42. GRB 001025B, Optical obervations
  43. GRB 991208: HST Imaging of the Host Galaxy
  44. GRB 001025B, I-band observations
  45. XMM-Newton observation of GRB001025
  46. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  47. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  48. GRB001007: Optical observations
  49. ASM Localization of GRB 001025
  50. GRB001007, Radio observations
  51. GRB 001018, Possible Radio Afterglow
  52. GRB001018, Gamma Ray Observations
  53. IPN TRIANGULATION OF GRB001019
  54. IPN TRIANGULATION OF GRB001018
  55. IPN TRIANGULATION OF GRB 001017
  56. V,R,I band observations of GRB000926
  57. HETE positions added to GCN
  58. GRB000926 - Amateur Optical Observations
  59. CONCAM null result on GRB001005
  60. IPN triangulation of GRB001005
  61. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  62. GRB000926 - Optical observations
  63. GRB000926 - Optical observations
  64. GRB 000926, Optical Decay
  65. GRB000911: VLT infrared observation
  66. GRB 000926, Optical Observations
  67. GRB000926 K'-band Observation
  68. J and K band observations of GRB 000926
  69. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  70. CONCAM crude optical limits before and after GRB000926
  71. GRB 000926: Preliminary R-band Lightcurve
  72. Spectroscopic Redshift of GRB 000926
  73. GRB 000926: Optical candidate
  74. Optical candidate for GRB000926
  75. GRB 000911, BVRI field photometry
  76. GRB000911, Radio and Optical observations
  77. GRB000911: Optical observations
  78. GRB000830, BVRI field photometry
  79. GRB000210, Optical observations
  80. "Snapshot" afterglow IDs and GRB 000830
  81. GRB000730, Gamma Ray Observations
  82. GRB000812, Radio observations
  83. GRB000801, Gamma Ray Observations
  84. GRB000801, VLT-Antu R-band observations
  85. GRB 991208 Host Galaxy Imaging
  86. IPN localization of GRB000730B
  87. GRB 990510: Possible detection of a host galaxy
  88. GRB 990510 Host Galaxy Discovery
  89. IPN localization of GRB000727
  90. GRB 990712: Late time HST/STIS Observations
  91. GRB 991216, HST/STIS observations
  92. GRB000620, Radio Observations
  93. GRB000630, optical observations
  94. GRB000630, Revised BVRI Field Photometry
  95. GRB000630, Optical Observations
  96. GRB000630, optical observations
  97. GRB000630, optical observations
  98. GRB000630, BVRI Field Photometry
  99. GRB000630, optical observations
  100. GRB000630: Optical observations

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