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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"

20815 results found.

  1. GRB000830, TNG B-band observations
  2. GRB000830, BVRI field photometry
  3. GRB000830: Optical observations
  4. GRB000830: Optical observations
  5. IPN triangulation of GRB000830
  6. IPN localization of GRB000820
  7. GRB000812, TNG R-band observations
  8. IPN localization of GRB000812
  9. IPN localization of GRB000811
  10. GRB000801, VLT-Antu R-band observations
  11. GRB 991208 Host Galaxy Imaging
  12. IPN localization of GRB000801
  13. IPN localization of GRB000730B
  14. IPN localization of GRB000730B
  15. IPN localization of GRB000730
  16. GRB 990510: Possible detection of a host galaxy
  17. GRB 990510 Host Galaxy Discovery
  18. IPN localization of GRB000727
  19. GRB 990712: Late time HST/STIS Observations
  20. GRB 991216, HST/STIS observations
  21. GRB000630, optical observations
  22. GRB000630, Revised BVRI Field Photometry
  23. GRB000630, Optical Observations
  24. GRB000630, optical observations
  25. GRB000630, optical observations
  26. GRB000630, BVRI Field Photometry
  27. GRB000630, optical observations
  28. GRB000630: Optical observations
  29. possible optical counterpart of GRB 000630
  30. IPN triangulation of GRB000630
  31. GRB 000620, optical observations
  32. GRB000418, HST/STIS Observations
  33. GRB990123: Late-time HST/STIS observations of the host
  34. GRB000623
  35. GRB000620, optical observations
  36. GRB000615: H-band observations
  37. GRB000620 - Optical observations
  38. GRB000620 Optical observations
  39. IPN annulus for GRB000620
  40. GRB000620: BeppoSAX WFC and GRBM detection
  41. GRB000607, optical observations
  42. GRB 000615: NIR further observations
  43. GRB990123, HST/STIS observations of the host galaxy
  44. GRB000616 optical observations
  45. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  46. GRB000616 [IPN Position]
  47. GRB000615B [IPN Position]
  48. GRB000615, further R-band photometry
  49. GRB 000615: NIR observations
  50. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  51. GRB000615, R-band photometry
  52. GRB 000301C: Further Late-Time HST/STIS observations
  53. GRB000528: follow-up X-ray measurements and update of IPN annulus
  54. Optical Follow-up of GRB000529 Error Box
  55. GRB000604 optical non-detection
  56. GRB000604 - Optical observations
  57. GRB000607, A SHORT, HARD BURST
  58. GRB000604, optical observations
  59. GRB000528, optical observations at ESO
  60. GRB 000604 optical observations
  61. GRB 000418: Detection of the Host Galaxy
  62. GRB000604, optical observations, comparison with DPOSS
  63. GRB000604 [IPN Position]
  64. GRB000528, Radio Observations
  65. X-ray Afterglow of GRB 000529
  66. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  67. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  68. GRB000529: Optical Observations
  69. IPN localization and time history of GRB000528
  70. IPN localization of GRB000529
  71. GRB 000528 - WFC measurements
  72. GRB000519, BVRI field photometry
  73. IPN triangulation of GRB000519
  74. IPN triangulation of GRB000516
  75. Re: GRB000508B : Optical observations
  76. GRB000508B, optical photometry
  77. GRB000508B, BVR field photometry
  78. Possible GRB-related phenomenon
  79. RXTE/ASM and IPN localization of GRB 000508B
  80. GRB000424, UBVRI field photometry
  81. GRB 000424 Optical Observations
  82. GRB000418, UBVRI field photometry update
  83. GRB000424, optical observations
  84. GRB 000429, optical observation
  85. GRB 000429, UBVRI field photometry
  86. IPN localization of GRB000429
  87. GRB 000418, UBVRI field photometry
  88. GRB 000418, optical observation
  89. GRB000424, optical observations
  90. GRB 000418, Optical Observation
  91. IPN error box for GRB000418
  92. GRB000419 [IPN Position]
  93. GRB000416 Optical Observations
  94. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  95. Budget cuts in BeppoSAX operations: impact on GRB observations
  96. GRB 000408, optical observations
  97. GRB 991208, UBVRI field photometry
  98. GRB000408, lotis optical observations
  99. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  100. GRB000301C - Addendum to GCN 623

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