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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"

24600 results found.

  1. GRB000620, Radio Observations
  2. GRB000630, optical observations
  3. GRB000630, Revised BVRI Field Photometry
  4. GRB000630, Optical Observations
  5. GRB000630, optical observations
  6. GRB000630, optical observations
  7. GRB000630, BVRI Field Photometry
  8. GRB000630, optical observations
  9. GRB000630: Optical observations
  10. GRB000630, Radio Observations
  11. possible optical counterpart of GRB 000630
  12. GRB 000620, optical observations
  13. GRB000418, HST/STIS Observations
  14. GRB990123: Late-time HST/STIS observations of the host
  15. GRB000620, optical observations
  16. GRB000615: H-band observations
  17. GRB990308, HST/STIS observations of the host galaxy
  18. GRB000620 - Optical observations
  19. GRB000620 Optical observations
  20. GRB000620: BeppoSAX WFC and GRBM detection
  21. GRB000607, optical observations
  22. GRB 000615: NIR further observations
  23. GRB990123, HST/STIS observations of the host galaxy
  24. GRB000616 optical observations
  25. GRB 000615, near-infrared observations
  26. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  27. GRB000615, further R-band photometry
  28. GRB 000615: NIR observations
  29. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  30. GRB000615, R-band photometry
  31. The Hosts of GRB 980703 and GRB 971214
  32. GRB 000301C: Further Late-Time HST/STIS observations
  33. GRB000528: follow-up X-ray measurements and update of IPN annulus
  34. GRB980519, HST/STIS observations of the host galaxy
  35. GRB000604 optical non-detection
  36. GRB000604 - Optical observations
  37. GRB000604, optical observations
  38. GRB000528, optical observations at ESO
  39. GRB 000604 optical observations
  40. GRB 000418: Detection of the Host Galaxy
  41. GRB000604, optical observations, comparison with DPOSS
  42. GRB000528, Radio Observations
  43. X-ray Afterglow of GRB 000529
  44. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  45. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  46. GRB 000528 - WFC measurements
  47. GRB000519, BVRI field photometry
  48. IPN triangulation of GRB000519
  49. GRB000508B, optical photometry
  50. GRB000508B, BVR field photometry
  51. Possible GRB-related phenomenon
  52. RXTE/ASM and IPN localization of GRB 000508B
  53. GRB000424, UBVRI field photometry
  54. GRB000418, UBVRI field photometry update
  55. GRB000424, optical observations
  56. GRB 000429, optical observation
  57. GRB 000429, UBVRI field photometry
  58. GRB 000418, UBVRI field photometry
  59. GRB 000418, optical observation
  60. GRB 000418, Optical Observation
  61. GRB000418, near-infrared observations
  62. Correction to IPN error box for GRB000419
  63. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  64. GRB000416 BRJK observations
  65. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  66. GRB 000408, optical observations
  67. GRB 991208, UBVRI field photometry
  68. GRB000408, lotis optical observations
  69. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  70. GRB000301C - Addendum to GCN 623
  71. GRB 000323, optical observations
  72. GRB 000326: Optical Observations
  73. GRB000326, Radio observations
  74. GRB000313, Radio observations
  75. GRB 000313 - optical transient in the BATSE error box
  76. GRB 000307, Optical Observations
  77. GRB 000307, BVRI Field Photometry
  78. GRB 000301C: A Precise Redshift Determination
  79. GRB 000301C, Optical Observation
  80. GRB 000301C: HST/STIS CCD Imaging of the field
  81. IPN error box for GRB000307
  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. GRB000301C, near-infrared observations (JHK' imaging)
  91. GRB 000301c near-IR observations
  92. GRB 000301C, UBVRI field photometry
  93. GRB 000301C: OT confirmed
  94. GRB000301c optical observations
  95. GRB000301C, optical observations
  96. GRB000301C
  97. GRB 000301C : Optical Candidate
  98. GRB000301C: RXTE/ASM and IPN localizations
  99. GRB000226 [IPN Position]
  100. HST Observations of GRB 990712

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