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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"

25220 results found.

  1. Spectroscopic Redshift of GRB 000926
  2. GRB 000926: Optical candidate
  3. Optical candidate for GRB000926
  4. GRB 000911, BVRI field photometry
  5. GRB000911, Radio and Optical observations
  6. GRB000911: Optical observations
  7. GRB000830, BVRI field photometry
  8. GRB000210, Optical observations
  9. "Snapshot" afterglow IDs and GRB 000830
  10. GRB000730, Gamma Ray Observations
  11. GRB000812, Radio observations
  12. GRB000801, Gamma Ray Observations
  13. GRB000801, VLT-Antu R-band observations
  14. GRB 991208 Host Galaxy Imaging
  15. IPN localization of GRB000730B
  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. GRB000620, Radio Observations
  22. GRB000630, optical observations
  23. GRB000630, Revised BVRI Field Photometry
  24. GRB000630, Optical Observations
  25. GRB000630, optical observations
  26. GRB000630, optical observations
  27. GRB000630, BVRI Field Photometry
  28. GRB000630, optical observations
  29. GRB000630: Optical observations
  30. GRB000630, Radio Observations
  31. possible optical counterpart of GRB 000630
  32. GRB 000620, optical observations
  33. GRB000418, HST/STIS Observations
  34. GRB990123: Late-time HST/STIS observations of the host
  35. GRB000620, optical observations
  36. GRB000615: H-band observations
  37. GRB990308, HST/STIS observations of the host galaxy
  38. GRB000620 - Optical observations
  39. GRB000620 Optical observations
  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 000615, near-infrared 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. The Hosts of GRB 980703 and GRB 971214
  52. GRB 000301C: Further Late-Time HST/STIS observations
  53. GRB000528: follow-up X-ray measurements and update of IPN annulus
  54. GRB980519, HST/STIS observations of the host galaxy
  55. GRB000604 optical non-detection
  56. GRB000604 - Optical observations
  57. GRB000604, optical observations
  58. GRB000528, optical observations at ESO
  59. GRB 000604 optical observations
  60. GRB 000418: Detection of the Host Galaxy
  61. GRB000604, optical observations, comparison with DPOSS
  62. GRB000528, Radio Observations
  63. X-ray Afterglow of GRB 000529
  64. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  65. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  66. GRB 000528 - WFC measurements
  67. GRB000519, BVRI field photometry
  68. IPN triangulation of GRB000519
  69. GRB000508B, optical photometry
  70. GRB000508B, BVR field photometry
  71. Possible GRB-related phenomenon
  72. RXTE/ASM and IPN localization of GRB 000508B
  73. GRB000424, UBVRI field photometry
  74. GRB000418, UBVRI field photometry update
  75. GRB000424, optical observations
  76. GRB 000429, optical observation
  77. GRB 000429, UBVRI field photometry
  78. GRB 000418, UBVRI field photometry
  79. GRB 000418, optical observation
  80. GRB 000418, Optical Observation
  81. GRB000418, near-infrared observations
  82. Correction to IPN error box for GRB000419
  83. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  84. GRB000416 BRJK observations
  85. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  86. GRB 000408, optical observations
  87. GRB 991208, UBVRI field photometry
  88. GRB000408, lotis optical observations
  89. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  90. GRB000301C - Addendum to GCN 623
  91. GRB 000323, optical observations
  92. GRB 000326: Optical Observations
  93. GRB000326, Radio observations
  94. GRB000313, Radio observations
  95. GRB 000313 - optical transient in the BATSE error box
  96. GRB 000307, Optical Observations
  97. GRB 000307, BVRI Field Photometry
  98. GRB 000301C: A Precise Redshift Determination
  99. GRB 000301C, Optical Observation
  100. GRB 000301C: HST/STIS CCD Imaging of the field

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