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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"

32420 results found.

  1. GRB 990308a and GRB 990308b
  2. GRB990308 (Trig. 7457), optical observations
  3. GRB981220, IPN localization
  4. GRB 981220, radio observations
  5. GRB 990123, Field Photometry
  6. GRB 990217 Optical Observations
  7. GRB 990217, radio observations
  8. Optical Observations of GRB990217
  9. GRB990123: Caltech STIS Photometry and Images
  10. GRB990123 observations
  11. GRB990123, Optical Observation
  12. GRB 990123: Discovery of the Probable Host Galaxy
  13. GRB 990123: Reduced HST Images
  14. For Immediate Posting to GCN - HST Data GRB 990123 Available
  15. GRB19990123 observations
  16. GRB 990123: BVRI standards in the field
  17. GRB 990123: Updated Keck Spectroscopy Results
  18. GRB981220, field photometry
  19. GRB 990123 NOT Spectrum Update
  20. GRB990123, Optical observation
  21. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  22. GRB 990123: Publicly available reduced HST images
  23. GRB990123, Upcoming HST Service Observations
  24. GRB 990123: New Constraints on Possible Foreground Galaxies
  25. GRB990123 Optical Observations
  26. GRB990123, Probability of gravitational lensing
  27. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  28. GRB 990123: Continued Radio Observations
  29. GRB990123, Preliminary Lens Search Results
  30. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  31. On the Lensing Interpretation of GRB 990123
  32. Search for Potential Images of GRB 990123
  33. Search for Potential Images of GRB 990123
  34. GRB990123, Optical BVRI Observations
  35. GRB 990123: near-infrared observations.
  36. GRB990123, OSSE observations
  37. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  38. "GRB 990123: New BV Observations"
  39. GRB 990123 Optical Follow-Up
  40. GRB 990123; Addendum to GCN 223
  41. GRB 990123: BATSE Observations
  42. GRB 990123 Keck Spectrum update
  43. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  44. GRB990123 Optical Observations
  45. GRB 990123 Spectroscopic Redshifts
  46. GRB 990123: New Optical Observations, Decay Measure
  47. GRB 990123 Optical Follow-Up
  48. GRB 990123: Possible Gravitationally Lensed Burst?
  49. GRB 990123 optical observations
  50. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  51. GRB 990123 radio observations
  52. GRB 990123, new radio source
  53. GRB990123, Optical observation
  54. GRB 990123: Optical Decay Slope
  55. GRB 990123 r-band photometry
  56. GRB 990123 Optical Follow-up
  57. GRB990123, early optical counterpart detection
  58. GRB990123 Optical Observation
  59. GRB 990123: Bright New Source, Possible Optical Transient
  60. GRB 990123, Radio observations
  61. SN 1999E & GRB 980919
  62. Possible identification of SN1999E with GRB980910
  63. Optical Observations of GRB 981220
  64. GRB 981226: radio variable
  65. GRB981220
  66. GRB981220, Optical Observations
  67. GRB 981220 Optical observations
  68. GRB 981226 Optical Observations
  69. GRB 980613: Spectroscopy of the host galaxy
  70. GRB981226, sub-millimeter observations
  71. GRB981220, sub-millimeter observations
  72. GRB 981220 and GRB 981226, optical observations
  73. GRB 981226 radio observations
  74. GRB 981226
  75. GRB 981226 optical observations
  76. radio observations of GRB 981226
  77. GRB981220 B, R and I band observations
  78. GRB 981220:Optical Observations
  79. GRB 981220 optical R and I observations
  80. GRB981226, BeppoSAX Christmas GRB
  81. GRB 981226 - Infrared Observations
  82. GRB 981226 optical observations
  83. GRB 981220
  84. GRB 981220, radio observations
  85. GRB981226 Optical Observation
  86. GRB 981220, radio observations
  87. GRB 981220: BeppoSAX/GRBM results
  88. GRB981220 I-band Observations
  89. GRB 981220
  90. GRB 981220 Optical Observations
  91. GRB 981220, optical observations
  92. GRB 980326/Host Galaxy
  93. GRB981220 IPN error box
  94. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  95. GRB980329 R,I flux calibration and R,I,K upper limits
  96. GRB980425: X-ray revised positions
  97. GRB 980923 BATSE Observations
  98. GRB980703 Very Long Baseline Interferometry
  99. GRB970508 optical observations
  100. GRB971214, association with a Galactic star?

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