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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"

24594 results found.

  1. GRB000630, BVRI Field Photometry
  2. GRB000630, optical observations
  3. GRB000630: Optical observations
  4. GRB000630, Radio Observations
  5. possible optical counterpart of GRB 000630
  6. GRB 000620, optical observations
  7. GRB000418, HST/STIS Observations
  8. GRB990123: Late-time HST/STIS observations of the host
  9. GRB000620, optical observations
  10. GRB000615: H-band observations
  11. GRB990308, HST/STIS observations of the host galaxy
  12. GRB000620 - Optical observations
  13. GRB000620 Optical observations
  14. GRB000620: BeppoSAX WFC and GRBM detection
  15. GRB000607, optical observations
  16. GRB 000615: NIR further observations
  17. GRB990123, HST/STIS observations of the host galaxy
  18. GRB000616 optical observations
  19. GRB 000615, near-infrared observations
  20. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  21. GRB000615, further R-band photometry
  22. GRB 000615: NIR observations
  23. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  24. GRB000615, R-band photometry
  25. The Hosts of GRB 980703 and GRB 971214
  26. GRB 000301C: Further Late-Time HST/STIS observations
  27. GRB000528: follow-up X-ray measurements and update of IPN annulus
  28. GRB980519, HST/STIS observations of the host galaxy
  29. GRB000604 optical non-detection
  30. GRB000604 - Optical observations
  31. GRB000604, optical observations
  32. GRB000528, optical observations at ESO
  33. GRB 000604 optical observations
  34. GRB 000418: Detection of the Host Galaxy
  35. GRB000604, optical observations, comparison with DPOSS
  36. GRB000528, Radio Observations
  37. X-ray Afterglow of GRB 000529
  38. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  39. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  40. GRB 000528 - WFC measurements
  41. GRB000519, BVRI field photometry
  42. IPN triangulation of GRB000519
  43. GRB000508B, optical photometry
  44. GRB000508B, BVR field photometry
  45. Possible GRB-related phenomenon
  46. RXTE/ASM and IPN localization of GRB 000508B
  47. GRB000424, UBVRI field photometry
  48. GRB000418, UBVRI field photometry update
  49. GRB000424, optical observations
  50. GRB 000429, optical observation
  51. GRB 000429, UBVRI field photometry
  52. GRB 000418, UBVRI field photometry
  53. GRB 000418, optical observation
  54. GRB 000418, Optical Observation
  55. GRB000418, near-infrared observations
  56. Correction to IPN error box for GRB000419
  57. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  58. GRB000416 BRJK observations
  59. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  60. GRB 000408, optical observations
  61. GRB 991208, UBVRI field photometry
  62. GRB000408, lotis optical observations
  63. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  64. GRB000301C - Addendum to GCN 623
  65. GRB 000323, optical observations
  66. GRB 000326: Optical Observations
  67. GRB000326, Radio observations
  68. GRB000313, Radio observations
  69. GRB 000313 - optical transient in the BATSE error box
  70. GRB 000307, Optical Observations
  71. GRB 000307, BVRI Field Photometry
  72. GRB 000301C: A Precise Redshift Determination
  73. GRB 000301C, Optical Observation
  74. GRB 000301C: HST/STIS CCD Imaging of the field
  75. IPN error box for GRB000307
  76. GRB000301C, optical R-band observations
  77. GRB 000301C Optical Observations
  78. GRB 000301C: K' Observations
  79. GRB000301C OT candidate optical observations
  80. GRB000301C - Host galaxy not detected in R (?)
  81. Optical observations of GRB000301c
  82. GRB000301C, Radio observations
  83. GRB000301C, Radio observations
  84. GRB000301C, near-infrared observations (JHK' imaging)
  85. GRB 000301c near-IR observations
  86. GRB 000301C, UBVRI field photometry
  87. GRB 000301C: OT confirmed
  88. GRB000301c optical observations
  89. GRB000301C, optical observations
  90. GRB000301C
  91. GRB 000301C : Optical Candidate
  92. GRB000301C: RXTE/ASM and IPN localizations
  93. GRB000226 [IPN Position]
  94. HST Observations of GRB 990712
  95. GRB 000214 near-IR observations
  96. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  97. GRB000210, Radio Observations
  98. GRB 000115, BVRI field photometry
  99. GRB000214: BeppoSAX GRBM and WFC Detection
  100. Optical observations of GRB000210

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