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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"

37493 results found.

  1. GRB 990123: Continued Radio Observations
  2. GRB990123, Preliminary Lens Search Results
  3. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  4. On the Lensing Interpretation of GRB 990123
  5. Search for Potential Images of GRB 990123
  6. Search for Potential Images of GRB 990123
  7. GRB990123, Optical BVRI Observations
  8. GRB 990123: near-infrared observations.
  9. GRB990123, OSSE observations
  10. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  11. "GRB 990123: New BV Observations"
  12. GRB 990123 Optical Follow-Up
  13. GRB 990123; Addendum to GCN 223
  14. GRB 990123: BATSE Observations
  15. GRB 990123 Keck Spectrum update
  16. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  17. GRB990123 Optical Observations
  18. GRB 990123 Spectroscopic Redshifts
  19. GRB 990123: New Optical Observations, Decay Measure
  20. GRB 990123 Optical Follow-Up
  21. GRB 990123: Possible Gravitationally Lensed Burst?
  22. GRB 990123 optical observations
  23. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  24. GRB 990123 radio observations
  25. GRB 990123, new radio source
  26. GRB990123, Optical observation
  27. GRB 990123: Optical Decay Slope
  28. GRB 990123 r-band photometry
  29. GRB 990123 Optical Follow-up
  30. GRB990123, early optical counterpart detection
  31. GRB990123 Optical Observation
  32. GRB 990123: Bright New Source, Possible Optical Transient
  33. GRB 990123, Radio observations
  34. SN 1999E & GRB 980919
  35. Possible identification of SN1999E with GRB980910
  36. Optical Observations of GRB 981220
  37. GRB 981226: radio variable
  38. GRB981220
  39. GRB981220, Optical Observations
  40. GRB 981220 Optical observations
  41. GRB 981226 Optical Observations
  42. GRB 980613: Spectroscopy of the host galaxy
  43. GRB981226, sub-millimeter observations
  44. GRB981220, sub-millimeter observations
  45. GRB 981220 and GRB 981226, optical observations
  46. GRB 981226 radio observations
  47. GRB 981226
  48. GRB 981226 optical observations
  49. radio observations of GRB 981226
  50. GRB981220 B, R and I band observations
  51. GRB 981220:Optical Observations
  52. GRB 981220 optical R and I observations
  53. GRB981226, BeppoSAX Christmas GRB
  54. GRB 981226 - Infrared Observations
  55. GRB 981226 optical observations
  56. GRB 981220
  57. GRB 981220, radio observations
  58. GRB981226 Optical Observation
  59. GRB 981220, radio observations
  60. GRB 981220: BeppoSAX/GRBM results
  61. GRB981220 I-band Observations
  62. GRB 981220
  63. GRB 981220 Optical Observations
  64. GRB 981220, optical observations
  65. GRB 980326/Host Galaxy
  66. GRB981220 IPN error box
  67. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  68. GRB980329 R,I flux calibration and R,I,K upper limits
  69. GRB980425: X-ray revised positions
  70. GRB 980923 BATSE Observations
  71. GRB980703 Very Long Baseline Interferometry
  72. GRB970508 optical observations
  73. GRB971214, association with a Galactic star?
  74. Optical Observations of the Host Galaxy of GRB 980519
  75. GRB980519, Optical Observations
  76. GRB980703, Host galaxy multicolor photometry
  77. GRB980703 - BeppoSAX/GRBM detection
  78. GRB 980703 (NFI observations)
  79. GRB980703 optical photometry
  80. GRB 980703: BATSE Observations
  81. GRB980703: Radio transient
  82. GRB980703 H-band Observations
  83. GRB 980703: Spectrum of the proposed optical counterpart
  84. RXTE Observation of GRB 980706
  85. GRB980703: Spectrum of the proposed optical counterpart
  86. GRB980703 Transient Optical Follow-Up
  87. GRB980703: LOTIS observation at early times
  88. GRB980613 Optical Observations
  89. GRB 980703
  90. GRB 980703 H-band Observations
  91. GRB980703 (optical R observations)
  92. GRB980706
  93. GRB980703: radio source/optical transient
  94. BeppoSAX NFI observations of GRB 980703
  95. GRB 980703: ASM Position & Intensity
  96. GRB980703
  97. GRB980703 optical followup
  98. GRB 980613 Near-IR observations
  99. GRB980613, optical observations
  100. GRB 980613: Optical transient and its host galaxy

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