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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"

17042 results found.

  1. GRB010213, Near-IR observations
  2. Possible InfraRed Transient of GRB 010214.
  3. GRB010213 detected by HETE
  4. IPN Status Report
  5. HETE Status
  6. Optical Observations of GRB 001018 at Keck
  7. Optical observations of GRB 001018 with JCAM
  8. GRB 001212 Optical Observation
  9. GRB 001212 Optical Observation
  10. GRB001120, optical observations
  11. Optical/NIR observations of GRB001109
  12. GRB 001109: deep JHK upper limits
  13. GRB 001109 X-ray afterglow with BeppoSAX
  14. CORRECTION to XMM-Newton observation of GRB001025
  15. GRB001109: Optical observations
  16. GRB001109, Radio observations
  17. GRB001105 BVRI field photometry correction
  18. GRB001105, BVRI field photometry
  19. GRB 001025B, Optical obervations
  20. GRB 991208: HST Imaging of the Host Galaxy
  21. GRB 001025B, I-band observations
  22. GRB001007: Optical observations
  23. GRB001007, Radio observations
  24. IPN TRIANGULATION OF GRB 001017
  25. V,R,I band observations of GRB000926
  26. GRB000926 - Amateur Optical Observations
  27. CONCAM null result on GRB001005
  28. HETE-2 Launches Successfully
  29. HETE-2 48 hour Launch Delay
  30. GRB000926 - Optical observations
  31. GRB000926 - Optical observations
  32. GRB 000926, Optical Observations
  33. GRB000926 K'-band Observation
  34. J and K band observations of GRB 000926
  35. GRB 000926, optical observation by Oksanen (vsnet-grb)
  36. CONCAM crude optical limits before and after GRB000926
  37. GRB 000926 HST/Chandra TOO Status
  38. GRB 000926: Optical candidate
  39. Optical candidate for GRB000926
  40. GRB 000911, BVRI field photometry
  41. GRB000911, Radio and Optical observations
  42. GRB000911: Optical observations
  43. IPN triangulation of GRB000911
  44. GRB000830, BVRI field photometry
  45. IPN triangulation of GRB000830
  46. IPN localization of GRB000812
  47. GRB000801, VLT-Antu R-band observations
  48. GRB 991208 Host Galaxy Imaging
  49. Updated IPN coordinates for GRB000801
  50. IPN localization of GRB000801
  51. GRB 990510: Possible detection of a host galaxy
  52. GRB 990510 Host Galaxy Discovery
  53. GRB 990712: Late time HST/STIS Observations
  54. GRB 991216, HST/STIS observations
  55. GRB000630, optical observations
  56. GRB000630, Revised BVRI Field Photometry
  57. GRB000630, Optical Observations
  58. GRB000630, optical observations
  59. GRB000630, optical observations
  60. GRB000630, BVRI Field Photometry
  61. GRB000630, optical observations
  62. GRB000630: Optical observations
  63. possible optical counterpart of GRB 000630
  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. GRB000604, optical observations
  84. GRB000528, optical observations at ESO
  85. GRB 000418: Detection of the Host Galaxy
  86. GRB000604, optical observations, comparison with DPOSS
  87. GRB000528, Radio Observations
  88. X-ray Afterglow of GRB 000529
  89. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  90. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  91. GRB 000528 - WFC measurements
  92. GRB000519, BVRI field photometry
  93. GRB000508B, optical photometry
  94. GRB000508B, BVR field photometry
  95. Possible GRB-related phenomenon
  96. RXTE/ASM and IPN localization of GRB 000508B
  97. GRB000424, UBVRI field photometry
  98. GRB000418, UBVRI field photometry update
  99. GRB000424, optical observations
  100. GRB 000429, optical observation

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