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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"

25713 results found.

  1. GRB000210, Optical observations
  2. "Snapshot" afterglow IDs and GRB 000830
  3. GRB000730, Gamma Ray Observations
  4. GRB000812, Radio observations
  5. GRB000801, Gamma Ray Observations
  6. GRB000801, VLT-Antu R-band observations
  7. GRB 991208 Host Galaxy Imaging
  8. IPN localization of GRB000730B
  9. GRB 990510: Possible detection of a host galaxy
  10. GRB 990510 Host Galaxy Discovery
  11. IPN localization of GRB000727
  12. GRB 990712: Late time HST/STIS Observations
  13. GRB 991216, HST/STIS observations
  14. GRB000620, Radio Observations
  15. GRB000630, optical observations
  16. GRB000630, Revised BVRI Field Photometry
  17. GRB000630, Optical Observations
  18. GRB000630, optical observations
  19. GRB000630, optical observations
  20. GRB000630, BVRI Field Photometry
  21. GRB000630, optical observations
  22. GRB000630: Optical observations
  23. GRB000630, Radio Observations
  24. possible optical counterpart of GRB 000630
  25. GRB 000620, optical observations
  26. GRB000418, HST/STIS Observations
  27. GRB990123: Late-time HST/STIS observations of the host
  28. GRB000620, optical observations
  29. GRB000615: H-band observations
  30. GRB990308, HST/STIS observations of the host galaxy
  31. GRB000620 - Optical observations
  32. GRB000620 Optical observations
  33. GRB000620: BeppoSAX WFC and GRBM detection
  34. GRB000607, optical observations
  35. GRB 000615: NIR further observations
  36. GRB990123, HST/STIS observations of the host galaxy
  37. GRB000616 optical observations
  38. GRB 000615, near-infrared observations
  39. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  40. GRB000615, further R-band photometry
  41. GRB 000615: NIR observations
  42. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  43. GRB000615, R-band photometry
  44. The Hosts of GRB 980703 and GRB 971214
  45. GRB 000301C: Further Late-Time HST/STIS observations
  46. GRB000528: follow-up X-ray measurements and update of IPN annulus
  47. GRB980519, HST/STIS observations of the host galaxy
  48. GRB000604 optical non-detection
  49. GRB000604 - Optical observations
  50. GRB000604, optical observations
  51. GRB000528, optical observations at ESO
  52. GRB 000604 optical observations
  53. GRB 000418: Detection of the Host Galaxy
  54. GRB000604, optical observations, comparison with DPOSS
  55. GRB000528, Radio Observations
  56. X-ray Afterglow of GRB 000529
  57. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  58. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  59. GRB 000528 - WFC measurements
  60. GRB000519, BVRI field photometry
  61. IPN triangulation of GRB000519
  62. GRB000508B, optical photometry
  63. GRB000508B, BVR field photometry
  64. Possible GRB-related phenomenon
  65. RXTE/ASM and IPN localization of GRB 000508B
  66. GRB000424, UBVRI field photometry
  67. GRB000418, UBVRI field photometry update
  68. GRB000424, optical observations
  69. GRB 000429, optical observation
  70. GRB 000429, UBVRI field photometry
  71. GRB 000418, UBVRI field photometry
  72. GRB 000418, optical observation
  73. GRB 000418, Optical Observation
  74. GRB000418, near-infrared observations
  75. Correction to IPN error box for GRB000419
  76. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  77. GRB000416 BRJK observations
  78. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  79. GRB 000408, optical observations
  80. GRB 991208, UBVRI field photometry
  81. GRB000408, lotis optical observations
  82. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  83. GRB000301C - Addendum to GCN 623
  84. GRB 000323, optical observations
  85. GRB 000326: Optical Observations
  86. GRB000326, Radio observations
  87. GRB000313, Radio observations
  88. GRB 000313 - optical transient in the BATSE error box
  89. GRB 000307, Optical Observations
  90. GRB 000307, BVRI Field Photometry
  91. GRB 000301C: A Precise Redshift Determination
  92. GRB 000301C, Optical Observation
  93. GRB 000301C: HST/STIS CCD Imaging of the field
  94. IPN error box for GRB000307
  95. GRB000301C, optical R-band observations
  96. GRB 000301C Optical Observations
  97. GRB 000301C: K' Observations
  98. GRB000301C OT candidate optical observations
  99. GRB000301C - Host galaxy not detected in R (?)
  100. Optical observations of GRB000301c

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