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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"

16214 results found.

  1. HETE-2 48 hour Launch Delay
  2. GRB000926 - Optical observations
  3. GRB000926 - Optical observations
  4. GRB 000926, Optical Observations
  5. GRB000926 K'-band Observation
  6. J and K band observations of GRB 000926
  7. GRB 000926, optical observation by Oksanen (vsnet-grb)
  8. CONCAM crude optical limits before and after GRB000926
  9. GRB 000926 HST/Chandra TOO Status
  10. GRB 000926: Optical candidate
  11. Optical candidate for GRB000926
  12. GRB 000911, BVRI field photometry
  13. GRB000911, Radio and Optical observations
  14. GRB000911: Optical observations
  15. IPN triangulation of GRB000911
  16. GRB000830, BVRI field photometry
  17. IPN triangulation of GRB000830
  18. IPN localization of GRB000812
  19. GRB000801, VLT-Antu R-band observations
  20. GRB 991208 Host Galaxy Imaging
  21. Updated IPN coordinates for GRB000801
  22. IPN localization of GRB000801
  23. GRB 990510: Possible detection of a host galaxy
  24. GRB 990510 Host Galaxy Discovery
  25. GRB 990712: Late time HST/STIS Observations
  26. GRB 991216, HST/STIS observations
  27. GRB000630, optical observations
  28. GRB000630, Revised BVRI Field Photometry
  29. GRB000630, Optical Observations
  30. GRB000630, optical observations
  31. GRB000630, optical observations
  32. GRB000630, BVRI Field Photometry
  33. GRB000630, optical observations
  34. GRB000630: Optical observations
  35. possible optical counterpart of GRB 000630
  36. GRB 000620, optical observations
  37. GRB000418, HST/STIS Observations
  38. GRB990123: Late-time HST/STIS observations of the host
  39. GRB000620, optical observations
  40. GRB000620 - Optical observations
  41. GRB000620 Optical observations
  42. GRB000620: BeppoSAX WFC and GRBM detection
  43. GRB000607, optical observations
  44. GRB 000615: NIR further observations
  45. GRB000616 optical observations
  46. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  47. GRB000615, further R-band photometry
  48. GRB 000615: NIR observations
  49. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  50. GRB000615, R-band photometry
  51. GRB 000301C: Further Late-Time HST/STIS observations
  52. GRB000528: follow-up X-ray measurements and update of IPN annulus
  53. BeppoSAX X-ray transient/possible GRB000608
  54. GRB000604 - Optical observations
  55. GRB000604, optical observations
  56. GRB000528, optical observations at ESO
  57. GRB 000418: Detection of the Host Galaxy
  58. GRB000604, optical observations, comparison with DPOSS
  59. GRB000528, Radio Observations
  60. X-ray Afterglow of GRB 000529
  61. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  62. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  63. GRB 000528 - WFC measurements
  64. GRB000519, BVRI field photometry
  65. GRB000508B, optical photometry
  66. GRB000508B, BVR field photometry
  67. Possible GRB-related phenomenon
  68. RXTE/ASM and IPN localization of GRB 000508B
  69. GRB000424, UBVRI field photometry
  70. GRB000418, UBVRI field photometry update
  71. GRB000424, optical observations
  72. GRB 000429, optical observation
  73. GRB 000429, UBVRI field photometry
  74. GRB 000418, UBVRI field photometry
  75. GRB 000418, optical observation
  76. GRB 000418, Optical Observation
  77. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  78. GRB 000408, optical observations
  79. Refined IPN error box for GRB000408
  80. GRB 991208, UBVRI field photometry
  81. GRB000408: Optical CCD Observations from MIRO
  82. GRB000408, lotis optical observations
  83. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  84. GRB000408 [IPN Position]
  85. GRB000301C - Addendum to GCN 623
  86. GRB 000326: Optical Observations
  87. GRB000326, Radio observations
  88. GRB000313, Radio observations
  89. GRB 000313 - optical transient in the BATSE error box
  90. GRB 000307, BVRI Field Photometry
  91. GRB 000301C: HST/STIS CCD Imaging of the field
  92. GRB 000301C Optical Observations
  93. GRB 000301C: K' Observations
  94. GRB000301C - Host galaxy not detected in R (?)
  95. Optical observations of GRB000301c
  96. GRB000301C, Radio observations
  97. GRB000301C, Radio observations
  98. GRB 000301c near-IR observations
  99. GRB 000301C, UBVRI field photometry
  100. GRB 000301C: OT confirmed

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