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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"

24978 results found.

  1. GRB990123, HST/STIS observations of the host galaxy
  2. GRB000616 optical observations
  3. GRB 000615, near-infrared observations
  4. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  5. GRB000615, further R-band photometry
  6. GRB 000615: NIR observations
  7. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  8. GRB000615, R-band photometry
  9. The Hosts of GRB 980703 and GRB 971214
  10. GRB 000301C: Further Late-Time HST/STIS observations
  11. GRB000528: follow-up X-ray measurements and update of IPN annulus
  12. GRB980519, HST/STIS observations of the host galaxy
  13. GRB000604 optical non-detection
  14. GRB000604 - Optical observations
  15. GRB000604, optical observations
  16. GRB000528, optical observations at ESO
  17. GRB 000604 optical observations
  18. GRB 000418: Detection of the Host Galaxy
  19. GRB000604, optical observations, comparison with DPOSS
  20. GRB000528, Radio Observations
  21. X-ray Afterglow of GRB 000529
  22. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  23. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  24. GRB 000528 - WFC measurements
  25. GRB000519, BVRI field photometry
  26. IPN triangulation of GRB000519
  27. GRB000508B, optical photometry
  28. GRB000508B, BVR field photometry
  29. Possible GRB-related phenomenon
  30. RXTE/ASM and IPN localization of GRB 000508B
  31. GRB000424, UBVRI field photometry
  32. GRB000418, UBVRI field photometry update
  33. GRB000424, optical observations
  34. GRB 000429, optical observation
  35. GRB 000429, UBVRI field photometry
  36. GRB 000418, UBVRI field photometry
  37. GRB 000418, optical observation
  38. GRB 000418, Optical Observation
  39. GRB000418, near-infrared observations
  40. Correction to IPN error box for GRB000419
  41. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  42. GRB000416 BRJK observations
  43. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  44. GRB 000408, optical observations
  45. GRB 991208, UBVRI field photometry
  46. GRB000408, lotis optical observations
  47. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  48. GRB000301C - Addendum to GCN 623
  49. GRB 000323, optical observations
  50. GRB 000326: Optical Observations
  51. GRB000326, Radio observations
  52. GRB000313, Radio observations
  53. GRB 000313 - optical transient in the BATSE error box
  54. GRB 000307, Optical Observations
  55. GRB 000307, BVRI Field Photometry
  56. GRB 000301C: A Precise Redshift Determination
  57. GRB 000301C, Optical Observation
  58. GRB 000301C: HST/STIS CCD Imaging of the field
  59. IPN error box for GRB000307
  60. GRB000301C, optical R-band observations
  61. GRB 000301C Optical Observations
  62. GRB 000301C: K' Observations
  63. GRB000301C OT candidate optical observations
  64. GRB000301C - Host galaxy not detected in R (?)
  65. Optical observations of GRB000301c
  66. GRB000301C, Radio observations
  67. GRB000301C, Radio observations
  68. GRB000301C, near-infrared observations (JHK' imaging)
  69. GRB 000301c near-IR observations
  70. GRB 000301C, UBVRI field photometry
  71. GRB 000301C: OT confirmed
  72. GRB000301c optical observations
  73. GRB000301C, optical observations
  74. GRB000301C
  75. GRB 000301C : Optical Candidate
  76. GRB000301C: RXTE/ASM and IPN localizations
  77. GRB000226 [IPN Position]
  78. HST Observations of GRB 990712
  79. GRB 000214 near-IR observations
  80. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  81. GRB000210, Radio Observations
  82. GRB 000115, BVRI field photometry
  83. GRB000214: BeppoSAX GRBM and WFC Detection
  84. Optical observations of GRB000210
  85. GRB000210 X-ray afterglow
  86. GRB000214: X-ray afterglow candidate
  87. GRB000214 refined BeppoSAX-WFC position
  88. GRB 000210: BATSE Observations
  89. Optical observations of the Chandra X-ray source for GRB000210
  90. GRB000210, Radio Observations
  91. IPN triangulation of GRB000210
  92. GRB000210: possible afterglow detection with BeppoSAX NFI
  93. GRB000201, Radio Observations
  94. GRB000210: BeppoSAX GRBM and WFC Detection
  95. SAX_WFC_GRB_NOTICE
  96. SAX_WFC_GRB_NOTICE
  97. GRB000201 Optical Observations
  98. GRB 000201: TAROT optical observations
  99. GRB 991208, radio observations
  100. BATSE+IPN location of GRB000131

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