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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"

23576 results found.

  1. GRB 990506 R band observations
  2. GRB 990510: BATSE Observations
  3. GRB 990510 Optical Observations
  4. GRB 990510, BVI photometry
  5. GRB 990510 optical observations
  6. GRB 990510: BeppoSAX/GRBM observations
  7. GRB990510 optical observations
  8. GRB 990510 optical observations
  9. IPN localization of GRB990510
  10. GRB 990123, optical monitoring
  11. GRB 990506: BATSE Observations
  12. GRB 990506 optical observations
  13. GRB 990506, optical observations
  14. GRB990506 observation plan
  15. Refined IPN error box for GRB990506
  16. GRB 990506: Limits on the possible optical transient
  17. GRB 990506, optical observations
  18. GRB990506 Optical observations
  19. GRB990506 observation plan
  20. New IPN/RXTE error box for GRB990506
  21. IPN localization for GRB990506
  22. GRB 970228: Redshift and properties of the host galaxy
  23. IPN localization of GRB990427
  24. GRB980425 Optical observations of exponential decline at late time
  25. GRB990321 REFINED IPN ANNULUS
  26. GRB990323 PRECISE IPN POSITION
  27. GRB990321 IPN TRIANGULATION
  28. GRB 990316 Optical Observations
  29. GRB 990316 optical observations
  30. GRB990316 - Optical null results
  31. ASM/IPN error box for GRB 990308 (BATSE #7457)
  32. GRB990308 (Trig. 7457), optical observations
  33. GRB990308, Possible new SGR~0209+70
  34. GRB981220, IPN localization
  35. GRB 990123, Field Photometry
  36. GRB 990217 Optical Observations
  37. GRB 990217, radio observations
  38. GRB990217: BeppoSAX/GRBM data
  39. GRB990123 observations
  40. GRB990217 Optical observation
  41. GRB990123, Optical Observation
  42. GRB 990123: Discovery of the Probable Host Galaxy
  43. GRB 990123: Reduced HST Images
  44. GRB19990123 observations
  45. GRB 990123: BVRI standards in the field
  46. GRB 990123: Updated Keck Spectroscopy Results
  47. GRB981220, field photometry
  48. GRB 990123 NOT Spectrum Update
  49. GRB 990123: Publicly available reduced HST images
  50. GRB 990123: New Constraints on Possible Foreground Galaxies
  51. GRB990123, Probability of gravitational lensing
  52. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  53. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  54. GRB990123, OSSE observations
  55. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  56. GRB990123, ASCA X-ray observation of afterglow
  57. GRB 990123 Optical Follow-Up
  58. GRB 990123: BATSE Observations
  59. GRB990123 IPN annulus
  60. GRB990123 Optical Observations
  61. GRB 990123 Spectroscopic Redshifts
  62. GRB 990123: New Optical Observations, Decay Measure
  63. GRB 990123 Optical Follow-Up
  64. GRB 990123: Possible Gravitationally Lensed Burst?
  65. GRB990123, optical observation
  66. GRB990123 optical observations
  67. GRB990123, Optical observation
  68. GRB 990123: Optical Decay Slope
  69. GRB990123 Optical Observation
  70. GRB990123, BeppoSAX-NFI X-ray afterglow detection
  71. GRB990123, refined SAX-WFC position
  72. Possible identification of SN1999E with GRB980910
  73. Optical Observations of GRB 981220
  74. GRB981220
  75. GRB981220, Optical Observations
  76. GRB 981220 Optical observations
  77. GRB 981226 Optical Observations
  78. GRB 980613: Spectroscopy of the host galaxy
  79. GRB981226 Optical Observations
  80. GRB981226 BeppoSAX follow up
  81. GRB 981226
  82. GRB981220 B, R and I band observations
  83. GRB981226, BeppoSAX-NFI follow-up
  84. Optical Observations of GRB981226
  85. GRB 981220:Optical Observations
  86. GRB 981220 optical R and I observations
  87. GRB 981226 - Infrared Observations
  88. GRB 981220
  89. GRB981226 Optical Observation
  90. GRB 981220: BeppoSAX/GRBM results
  91. GRB981220 I-band Observations
  92. GRB 981220
  93. GRB 981220, optical observations
  94. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  95. BeppoSAX NFI Observation of GRB980425
  96. SGR1900+14, BeppoSAX-GRBM observations
  97. GRB980519, Optical Observations
  98. GRB980703, Host galaxy multicolor photometry
  99. GRB980703 - BeppoSAX/GRBM detection
  100. GRB980703 optical photometry

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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