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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"

27394 results found.

  1. GRB 010220, simultaneous optical observations
  2. GRB010220: BeppoSAX WFC and GRBM preliminary data
  3. GRB010214, candidate optical afterglow
  4. GRB010214, optical observations
  5. GRB010214: BeppoSAX WFC and GRBM preliminary data
  6. GRB 010214: X-Ray afterglow
  7. GRB 010214 optical observation
  8. GRB010213, Radio Observations
  9. J-Band Observation of GRB 010214.
  10. GRB010213, Near-IR observations
  11. Possible InfraRed Transient of GRB 010214.
  12. GRB 010214, optical observations
  13. GRB010213 detected by HETE
  14. IPN Status Report
  15. HETE Status
  16. IPN/RXTE TRIANGULATION OF GRB010126
  17. GRB010126 Optical Observations
  18. IPN TRIANGULATION OF GRB010126
  19. Optical Observations of GRB 001018 at Keck
  20. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  21. Optical observations of GRB 001018 with JCAM
  22. IPN TRIANGULATION OF GRB010115
  23. IPN TRIANGULATION OF GRB010109
  24. IPN TRIANGULATION OF GRB010109
  25. IPN triangulation of GRB010104
  26. IPN triangulation of GRB010103
  27. H band observation of GRB 001212
  28. IPN triangulation of GRB001219
  29. GRB 001212 Optical Observation
  30. GRB 001212 Optical Observation
  31. GRB 001212 possible OA in 2MASS
  32. IPN triangulation of GRB001212
  33. Confirmation of IPN position for GRB001204
  34. IPN triangulation of GRB001204 (short/hard)
  35. GRB001120, optical observations
  36. WSRT 4.8 GHz observations of GRB001109
  37. IPN triangulation of GRB001120
  38. GRB 001109: deep JHK upper limits
  39. GRB 001109 X-ray afterglow with BeppoSAX
  40. CORRECTION to XMM-Newton observation of GRB001025
  41. GRB001109, Radio observations
  42. GRB001105 BVRI field photometry correction
  43. GRB001105, BVRI field photometry
  44. IPN TRIANGULATION OF GRB001105
  45. GRB 001025B, Optical obervations
  46. GRB 991208: HST Imaging of the Host Galaxy
  47. GRB 001025B, I-band observations
  48. XMM-Newton observation of GRB001025
  49. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  50. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  51. GRB001007: Optical observations
  52. ASM Localization of GRB 001025
  53. GRB001007, Radio observations
  54. GRB 001018, Possible Radio Afterglow
  55. GRB001018, Gamma Ray Observations
  56. IPN TRIANGULATION OF GRB001019
  57. IPN TRIANGULATION OF GRB001018
  58. IPN TRIANGULATION OF GRB 001017
  59. V,R,I band observations of GRB000926
  60. HETE positions added to GCN
  61. GRB000926 - Amateur Optical Observations
  62. CONCAM null result on GRB001005
  63. IPN triangulation of GRB001005
  64. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  65. GRB000926 - Optical observations
  66. GRB000926 - Optical observations
  67. GRB 000926, Optical Decay
  68. GRB000911: VLT infrared observation
  69. GRB 000926, Optical Observations
  70. GRB000926 K'-band Observation
  71. J and K band observations of GRB 000926
  72. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  73. CONCAM crude optical limits before and after GRB000926
  74. GRB 000926: Preliminary R-band Lightcurve
  75. Spectroscopic Redshift of GRB 000926
  76. GRB 000926: Optical candidate
  77. Optical candidate for GRB000926
  78. GRB 000911, BVRI field photometry
  79. GRB000911, Radio and Optical observations
  80. GRB000911: Optical observations
  81. GRB000830, BVRI field photometry
  82. GRB000210, Optical observations
  83. "Snapshot" afterglow IDs and GRB 000830
  84. GRB000730, Gamma Ray Observations
  85. GRB000812, Radio observations
  86. GRB000801, Gamma Ray Observations
  87. GRB000801, VLT-Antu R-band observations
  88. GRB 991208 Host Galaxy Imaging
  89. IPN localization of GRB000730B
  90. GRB 990510: Possible detection of a host galaxy
  91. GRB 990510 Host Galaxy Discovery
  92. IPN localization of GRB000727
  93. GRB 990712: Late time HST/STIS Observations
  94. GRB 991216, HST/STIS observations
  95. GRB000620, Radio Observations
  96. GRB000630, optical observations
  97. GRB000630, Revised BVRI Field Photometry
  98. GRB000630, Optical Observations
  99. GRB000630, optical observations
  100. GRB000630, optical observations

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