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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"

26507 results found.

  1. GRB010222 further R-band photometry
  2. GRB010222, possible increase of optical decay slope
  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: Optical decay slope
  9. GRB 010214, Optical Observations
  10. GRB010222, radio observations
  11. GRB010222, optical observations
  12. GRB010222: BeppoSAX/NFI Observations
  13. GRB010214B,Gamma Ray Observations
  14. GRB 010220, simultaneous optical observations
  15. GRB010220: BeppoSAX WFC and GRBM preliminary data
  16. GRB010214, candidate optical afterglow
  17. GRB010214, optical observations
  18. GRB010214: BeppoSAX WFC and GRBM preliminary data
  19. GRB 010214: X-Ray afterglow
  20. GRB 010214 optical observation
  21. GRB010213, Radio Observations
  22. J-Band Observation of GRB 010214.
  23. GRB010213, Near-IR observations
  24. Possible InfraRed Transient of GRB 010214.
  25. GRB 010214, optical observations
  26. GRB010213 detected by HETE
  27. IPN Status Report
  28. HETE Status
  29. IPN/RXTE TRIANGULATION OF GRB010126
  30. GRB010126 Optical Observations
  31. IPN TRIANGULATION OF GRB010126
  32. Optical Observations of GRB 001018 at Keck
  33. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  34. Optical observations of GRB 001018 with JCAM
  35. IPN TRIANGULATION OF GRB010115
  36. IPN TRIANGULATION OF GRB010109
  37. IPN TRIANGULATION OF GRB010109
  38. IPN triangulation of GRB010104
  39. IPN triangulation of GRB010103
  40. H band observation of GRB 001212
  41. IPN triangulation of GRB001219
  42. GRB 001212 Optical Observation
  43. GRB 001212 Optical Observation
  44. GRB 001212 possible OA in 2MASS
  45. IPN triangulation of GRB001212
  46. Confirmation of IPN position for GRB001204
  47. IPN triangulation of GRB001204 (short/hard)
  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. IPN TRIANGULATION OF GRB001105
  58. GRB 001025B, Optical obervations
  59. GRB 991208: HST Imaging of the Host Galaxy
  60. GRB 001025B, I-band observations
  61. XMM-Newton observation of GRB001025
  62. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  63. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  64. GRB001007: Optical observations
  65. ASM Localization of GRB 001025
  66. GRB001007, Radio observations
  67. GRB 001018, Possible Radio Afterglow
  68. GRB001018, Gamma Ray Observations
  69. IPN TRIANGULATION OF GRB001019
  70. IPN TRIANGULATION OF GRB001018
  71. IPN TRIANGULATION OF GRB 001017
  72. V,R,I band observations of GRB000926
  73. HETE positions added to GCN
  74. GRB000926 - Amateur Optical Observations
  75. CONCAM null result on GRB001005
  76. IPN triangulation of GRB001005
  77. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  78. GRB000926 - Optical observations
  79. GRB000926 - Optical observations
  80. GRB 000926, Optical Decay
  81. GRB000911: VLT infrared observation
  82. GRB 000926, Optical Observations
  83. GRB000926 K'-band Observation
  84. J and K band observations of GRB 000926
  85. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  86. CONCAM crude optical limits before and after GRB000926
  87. GRB 000926: Preliminary R-band Lightcurve
  88. Spectroscopic Redshift of GRB 000926
  89. GRB 000926: Optical candidate
  90. Optical candidate for GRB000926
  91. GRB 000911, BVRI field photometry
  92. GRB000911, Radio and Optical observations
  93. GRB000911: Optical observations
  94. GRB000830, BVRI field photometry
  95. GRB000210, Optical observations
  96. "Snapshot" afterglow IDs and GRB 000830
  97. GRB000730, Gamma Ray Observations
  98. GRB000812, Radio observations
  99. GRB000801, Gamma Ray Observations
  100. GRB000801, VLT-Antu R-band observations

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