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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"

26365 results found.

  1. GRB 990506 optical observations
  2. GRB 990506, optical observations
  3. GRB 990506, armchair astronomy
  4. GRB 990506, optical observations from +1 to +3 hours
  5. GRB 990506, optical observations
  6. GRB990506 observation plan
  7. IPN localization for GRB990506
  8. GRB990323 PRECISE IPN POSITION
  9. GRB 990316 Optical Observations
  10. GRB 990316 optical observations
  11. GRB990316: simultaneous optical observation
  12. GRB990316 - Optical null results
  13. GRB990308 not a new SGR
  14. GRB 990308a and GRB 990308b
  15. GRB990308, Possible new SGR~0209+70
  16. GRB 990123, Field Photometry
  17. GRB 990217 Optical Observations
  18. BATSE Flight Anomaly
  19. GRB990217: BeppoSAX/GRBM data
  20. GRB990123 observations
  21. GRB990217 Optical observation
  22. GRB990123, Optical Observation
  23. GRB 990123: Discovery of the Probable Host Galaxy
  24. GRB 990123: Reduced HST Images
  25. GRB19990123 observations
  26. GRB 990123: BVRI standards in the field
  27. GRB981220, field photometry
  28. GRB990123, Optical observation
  29. GRB990123, 15-GHz limits
  30. GRB 990123: New Constraints on Possible Foreground Galaxies
  31. GRB990123 Optical Observations
  32. GRB990123, Probability of gravitational lensing
  33. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  34. GRB990123, Preliminary Lens Search Results
  35. On the Lensing Interpretation of GRB 990123
  36. Search for Potential Images of GRB 990123
  37. Search for Potential Images of GRB 990123
  38. GRB990123, Optical BVRI Observations
  39. GRB 990123: near-infrared observations.
  40. GRB990123, OSSE observations
  41. GRB990123: NIR Observation
  42. GRB990123, ASCA X-ray observation of afterglow
  43. "GRB 990123: New BV Observations"
  44. GRB 990123 Optical Follow-Up
  45. GRB 990123: BATSE Observations
  46. GRB990123 Optical Observations
  47. GRB 990123: New Optical Observations, Decay Measure
  48. GRB 990123 Optical Follow-Up
  49. GRB 990123: Possible Gravitationally Lensed Burst?
  50. GRB990123, optical observation
  51. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  52. GRB990123, Optical observation
  53. GRB 990123: Optical Decay Slope
  54. GRB 990123 r-band photometry
  55. GRB 990123 Optical Follow-up
  56. GRB990123, early optical counterpart detection
  57. GRB990123 Optical Observation
  58. Possible identification of SN1999E with GRB980910
  59. Optical Observations of GRB 981220
  60. GRB 981226: radio variable
  61. GRB981220
  62. GRB981220, Correction to GCN 179
  63. GRB 981220 Optical observations
  64. GRB 981226 Optical Observations
  65. GRB 981220 and GRB 981226, optical observations
  66. GRB981226 Optical Observations
  67. GRB981226 BeppoSAX follow up
  68. GRB 981226
  69. GRB 981226 optical observations
  70. GRB981220 B, R and I band observations
  71. Optical Observations of GRB981226
  72. GRB 981220:Optical Observations
  73. GRB 981226 optical observations
  74. GRB 981220
  75. GRB 981220, radio observations
  76. GRB981220 I-band Observations
  77. GRB 981220
  78. GRB 980326/Host Galaxy
  79. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  80. BeppoSAX NFI Observation of GRB980425
  81. GRB980329 R,I flux calibration and R,I,K upper limits
  82. GRB980425 Optical Follow-up
  83. GRB 980923 BATSE Observations
  84. SGR1900+14, BeppoSAX-GRBM observations
  85. GRB970508 optical observations
  86. GRB971214, association with a Galactic star?
  87. GRB980519, Optical Observations
  88. GRB980703 - BeppoSAX/GRBM detection
  89. GRB980703 optical photometry
  90. GRB 980703: BATSE Observations
  91. GRB980703 optical observations
  92. GRB980703: Radio transient
  93. GRB 980703: Spectrum of the proposed optical counterpart
  94. GRB980703 Transient Optical Follow-Up
  95. GRB980703: LOTIS observation at early times
  96. GRB980613 Optical Observations
  97. GRB980703 (I band observations)
  98. BeppoSAX NFI observations of GRB 980703
  99. GRB980519 observation report
  100. GRB980703 optical followup

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