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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"

18332 results found.

  1. Optical/NIR observations of GRB001109
  2. GRB 001109: deep JHK upper limits
  3. GRB 001109 X-ray afterglow with BeppoSAX
  4. CORRECTION to XMM-Newton observation of GRB001025
  5. GRB001109: Optical observations
  6. GRB001109, Radio observations
  7. GRB001105 BVRI field photometry correction
  8. GRB001105, BVRI field photometry
  9. GRB 001025B, Optical obervations
  10. GRB 991208: HST Imaging of the Host Galaxy
  11. GRB 001025B, I-band observations
  12. GRB001007: Optical observations
  13. GRB001007, Radio observations
  14. IPN TRIANGULATION OF GRB 001017
  15. V,R,I band observations of GRB000926
  16. GRB000926 - Amateur Optical Observations
  17. CONCAM null result on GRB001005
  18. HETE-2 Launches Successfully
  19. HETE-2 48 hour Launch Delay
  20. GRB000926 - Optical observations
  21. GRB000926 - Optical observations
  22. GRB 000926, Optical Observations
  23. GRB000926 K'-band Observation
  24. J and K band observations of GRB 000926
  25. GRB 000926, optical observation by Oksanen (vsnet-grb)
  26. CONCAM crude optical limits before and after GRB000926
  27. GRB 000926 HST/Chandra TOO Status
  28. GRB 000926: Optical candidate
  29. Optical candidate for GRB000926
  30. GRB 000911, BVRI field photometry
  31. GRB000911, Radio and Optical observations
  32. GRB000911: Optical observations
  33. IPN triangulation of GRB000911
  34. GRB000830, BVRI field photometry
  35. IPN triangulation of GRB000830
  36. IPN localization of GRB000812
  37. GRB000801, VLT-Antu R-band observations
  38. GRB 991208 Host Galaxy Imaging
  39. Updated IPN coordinates for GRB000801
  40. IPN localization of GRB000801
  41. GRB 990510: Possible detection of a host galaxy
  42. GRB 990510 Host Galaxy Discovery
  43. GRB 990712: Late time HST/STIS Observations
  44. GRB 991216, HST/STIS observations
  45. GRB000630, optical observations
  46. GRB000630, Revised BVRI Field Photometry
  47. GRB000630, Optical Observations
  48. GRB000630, optical observations
  49. GRB000630, optical observations
  50. GRB000630, BVRI Field Photometry
  51. GRB000630, optical observations
  52. GRB000630: Optical observations
  53. possible optical counterpart of GRB 000630
  54. GRB 000620, optical observations
  55. GRB000418, HST/STIS Observations
  56. GRB990123: Late-time HST/STIS observations of the host
  57. GRB000620, optical observations
  58. GRB000620 - Optical observations
  59. GRB000620 Optical observations
  60. GRB000620: BeppoSAX WFC and GRBM detection
  61. GRB000607, optical observations
  62. GRB 000615: NIR further observations
  63. GRB000616 optical observations
  64. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  65. GRB000615, further R-band photometry
  66. GRB 000615: NIR observations
  67. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  68. GRB000615, R-band photometry
  69. GRB 000301C: Further Late-Time HST/STIS observations
  70. GRB000528: follow-up X-ray measurements and update of IPN annulus
  71. BeppoSAX X-ray transient/possible GRB000608
  72. GRB000604 - Optical observations
  73. GRB000604, optical observations
  74. GRB000528, optical observations at ESO
  75. GRB 000418: Detection of the Host Galaxy
  76. GRB000604, optical observations, comparison with DPOSS
  77. GRB000528, Radio Observations
  78. X-ray Afterglow of GRB 000529
  79. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  80. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  81. GRB 000528 - WFC measurements
  82. GRB000519, BVRI field photometry
  83. GRB000508B, optical photometry
  84. GRB000508B, BVR field photometry
  85. Possible GRB-related phenomenon
  86. RXTE/ASM and IPN localization of GRB 000508B
  87. GRB000424, UBVRI field photometry
  88. GRB000418, UBVRI field photometry update
  89. GRB000424, optical observations
  90. GRB 000429, optical observation
  91. GRB 000429, UBVRI field photometry
  92. GRB 000418, UBVRI field photometry
  93. GRB 000418, optical observation
  94. GRB 000418, Optical Observation
  95. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  96. GRB 000408, optical observations
  97. Refined IPN error box for GRB000408
  98. GRB 991208, UBVRI field photometry
  99. GRB000408: Optical CCD Observations from MIRO
  100. GRB000408, lotis optical observations

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