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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"

19863 results found.

  1. GRB 990510 Host Galaxy Discovery
  2. GRB 990712: Late time HST/STIS Observations
  3. GRB 991216, HST/STIS observations
  4. GRB000630, optical observations
  5. GRB000630, Revised BVRI Field Photometry
  6. GRB000630, Optical Observations
  7. GRB000630, optical observations
  8. GRB000630, optical observations
  9. GRB000630, BVRI Field Photometry
  10. GRB000630, optical observations
  11. GRB000630: Optical observations
  12. possible optical counterpart of GRB 000630
  13. GRB 000620, optical observations
  14. GRB000418, HST/STIS Observations
  15. GRB990123: Late-time HST/STIS observations of the host
  16. GRB000620, optical observations
  17. GRB000620 - Optical observations
  18. GRB000620 Optical observations
  19. GRB000620: BeppoSAX WFC and GRBM detection
  20. GRB000615, Radio observations
  21. GRB000607, optical observations
  22. GRB 000615: NIR further observations
  23. GRB000616 optical observations
  24. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  25. GRB000615, further R-band photometry
  26. GRB 000615: NIR observations
  27. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  28. GRB000615, R-band photometry
  29. GRB 000301C: Further Late-Time HST/STIS observations
  30. GRB000528: follow-up X-ray measurements and update of IPN annulus
  31. BeppoSAX X-ray transient/possible GRB000608
  32. GRB000604 - Optical observations
  33. GRB000604, optical observations
  34. GRB000528, optical observations at ESO
  35. GRB 000418: Detection of the Host Galaxy
  36. GRB000604, optical observations, comparison with DPOSS
  37. GRB000604 [IPN Position]
  38. GRB000528, Radio Observations
  39. X-ray Afterglow of GRB 000529
  40. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  41. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  42. GRB 000528 - WFC measurements
  43. GRB000529: BeppoSAX WFC position
  44. GRB000519, BVRI field photometry
  45. IPN triangulation of GRB000519
  46. GRB000508B, optical photometry
  47. GRB000508B, BVR field photometry
  48. Possible GRB-related phenomenon
  49. RXTE/ASM and IPN localization of GRB 000508B
  50. GRB000424, UBVRI field photometry
  51. GRB000418, UBVRI field photometry update
  52. GRB000424, optical observations
  53. GRB 000429, optical observation
  54. GRB 000429, UBVRI field photometry
  55. IPN localization of GRB000429
  56. GRB 000418, UBVRI field photometry
  57. GRB 000418, optical observation
  58. GRB 000418, Optical Observation
  59. IPN error box for GRB000418
  60. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  61. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  62. Budget cuts in BeppoSAX operations: impact on GRB observations
  63. GRB 000408, optical observations
  64. GRB 991208, UBVRI field photometry
  65. GRB000301c results
  66. GRB000408, lotis optical observations
  67. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  68. GRB000301C - Addendum to GCN 623
  69. GRB 000326: Optical Observations
  70. GRB000326, Radio observations
  71. GRB000326 [IPN Position]
  72. GRB000313, Radio observations
  73. GRB 000313 - optical transient in the BATSE error box
  74. GRB000301C - R photometry
  75. GRB 000307, Optical Observations
  76. GRB 000307, BVRI Field Photometry
  77. GRB 000301C: Optical Spectrum and Redshift
  78. GRB 000301C: Optical Spectrum and Redshift
  79. GRB 000301C: A Precise Redshift Determination
  80. GRB 000301C, Optical Observation
  81. GRB 000301C: HST/STIS CCD Imaging of the field
  82. GRB000301C, optical R-band observations
  83. GRB 000301C Optical Observations
  84. GRB 000301C: K' Observations
  85. GRB000301C OT candidate optical observations
  86. GRB000301C - Host galaxy not detected in R (?)
  87. Optical observations of GRB000301c
  88. GRB000301C, Radio observations
  89. GRB000301C, Radio observations
  90. GRB 000301c near-IR observations
  91. GRB 000301C, UBVRI field photometry
  92. GRB000301C 250 GHz detection
  93. GRB 000301C R-band observation
  94. GRB000301C, near-infrared observations (JHK' photometry)
  95. GRB 000301C: OT confirmed
  96. GRB000301c optical observations
  97. GRB000301C, optical observations
  98. GRB000301c, near-infrared observations
  99. GRB000301C
  100. GRB 000301C : Optical Candidate

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