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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"

19572 results found.

  1. Optical Observations of GRB 001018 at Keck
  2. Optical observations of GRB 001018 with JCAM
  3. IPN TRIANGULATION OF GRB010109
  4. IPN triangulation of GRB010104
  5. IPN triangulation of GRB010103
  6. IPN triangulation of GRB001219
  7. GRB 001212 Optical Observation
  8. GRB 001212 Optical Observation
  9. GRB001120, optical observations
  10. GRB 001109: deep JHK upper limits
  11. GRB 001109 X-ray afterglow with BeppoSAX
  12. CORRECTION to XMM-Newton observation of GRB001025
  13. GRB001109, Radio observations
  14. GRB001105 BVRI field photometry correction
  15. GRB001105, BVRI field photometry
  16. GRB 001025B, Optical obervations
  17. GRB 991208: HST Imaging of the Host Galaxy
  18. GRB 001025B, I-band observations
  19. GRB 001025A, optical observation
  20. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  21. GRB001007: Optical observations
  22. GRB001007, Radio observations
  23. IPN TRIANGULATION OF GRB001020
  24. CORRECTION TO PEAK FLUX OF GRB001018
  25. IPN TRIANGULATION OF GRB 001017
  26. V,R,I band observations of GRB000926
  27. GRB000926 - Amateur Optical Observations
  28. CONCAM null result on GRB001005
  29. GRB000926 - Optical observations
  30. GRB000926 - Optical observations
  31. GRB 000926, Optical Observations
  32. GRB000926 K'-band Observation
  33. J and K band observations of GRB 000926
  34. CONCAM crude optical limits before and after GRB000926
  35. GRB 000926: Optical candidate
  36. Optical candidate for GRB000926
  37. GRB 000911, BVRI field photometry
  38. GRB000911, Radio and Optical observations
  39. GRB000911: Optical observations
  40. False GRB alarm from RXTE/ASM on 8 Sept 2000
  41. GRB000830, BVRI field photometry
  42. GRB000830: Optical observations
  43. IPN localization of GRB000820
  44. IPN localization of GRB000812
  45. GRB000801, VLT-Antu R-band observations
  46. GRB 991208 Host Galaxy Imaging
  47. IPN localization of GRB000730B
  48. IPN localization of GRB000730B
  49. GRB 990510: Possible detection of a host galaxy
  50. GRB 990510 Host Galaxy Discovery
  51. GRB 990712: Late time HST/STIS Observations
  52. GRB 991216, HST/STIS observations
  53. GRB000630, optical observations
  54. GRB000630, Revised BVRI Field Photometry
  55. GRB000630, Optical Observations
  56. GRB000630, optical observations
  57. GRB000630, optical observations
  58. GRB000630, BVRI Field Photometry
  59. GRB000630, optical observations
  60. GRB000630, optical observations
  61. GRB000630: Optical observations
  62. possible optical counterpart of GRB 000630
  63. IPN triangulation of GRB000630
  64. GRB 000620, optical observations
  65. GRB000418, HST/STIS Observations
  66. GRB990123: Late-time HST/STIS observations of the host
  67. GRB000620, optical observations
  68. GRB000620 - Optical observations
  69. GRB000620 Optical observations
  70. GRB000620: BeppoSAX WFC and GRBM detection
  71. GRB000607, optical observations
  72. GRB 000615: NIR further observations
  73. GRB000616 optical observations
  74. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  75. GRB000615, further R-band photometry
  76. GRB 000615: NIR observations
  77. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  78. GRB000615, R-band photometry
  79. GRB 000301C: Further Late-Time HST/STIS observations
  80. GRB000528: follow-up X-ray measurements and update of IPN annulus
  81. BeppoSAX X-ray transient/possible GRB000608
  82. GRB000604 - Optical observations
  83. GRB000607, A SHORT, HARD BURST
  84. GRB000604, optical observations
  85. GRB000528, optical observations at ESO
  86. GRB 000418: Detection of the Host Galaxy
  87. GRB000604, optical observations, comparison with DPOSS
  88. GRB000528, Radio Observations
  89. X-ray Afterglow of GRB 000529
  90. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  91. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  92. GRB 000528 - WFC measurements
  93. GRB000519, BVRI field photometry
  94. GRB000508B, optical photometry
  95. GRB000508B, BVR field photometry
  96. Possible GRB-related phenomenon
  97. RXTE/ASM and IPN localization of GRB 000508B
  98. GRB000424, UBVRI field photometry
  99. GRB000418, UBVRI field photometry update
  100. GRB000424, optical observations

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