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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"

37079 results found.

  1. GRB990510: X-ray afterglow
  2. GRB 990510: optical observation
  3. VLT spectrum of GRB990510
  4. GRB 990510: Broad Band Break
  5. GRB 990510: BATSE Observations
  6. GRB 990510 Optical Observations
  7. GRB 990510, BVI photometry
  8. GRB 990510 optical observations
  9. GRB 990510: BeppoSAX/GRBM observations
  10. GRB990510 optical observations
  11. GRB 990510 optical observations
  12. GRB 990510 optical observations
  13. Galactic extinction towards GRB 990510
  14. GRB990510: NFI X-ray source
  15. GRB 990510 optical observations
  16. IPN localization of GRB990510
  17. GRB 990506 Radio Observations
  18. GRB 990123, optical monitoring
  19. GRB 990506: BATSE Observations
  20. GRB 990506, optical observations
  21. GRB 990510: Final BeppoSAX-WFC Coordinates
  22. GRB 990506, Optical Observations
  23. GRB 990506 optical observations
  24. GRB 990506 optical observations
  25. GRB 990506, optical observations
  26. GRB990506 observation plan
  27. Refined IPN error box for GRB990506
  28. GRB 990506: Limits on the possible optical transient
  29. GRB 990506, armchair astronomy
  30. GRB 990506, optical observations from +1 to +3 hours
  31. GRB 990506, optical observations
  32. GRB990506 observation plan
  33. New IPN/RXTE error box for GRB990506
  34. IPN localization for GRB990506
  35. GRB 970228: Redshift and properties of the host galaxy
  36. IPN localization of GRB990427
  37. GRB981220 VLBA observations
  38. GRB980425 Optical observations of exponential decline at late time
  39. GRB990321 REFINED IPN ANNULUS
  40. GRB990323 PRECISE IPN POSITION
  41. GRB990321 IPN TRIANGULATION
  42. GRB 990316 Optical Observations
  43. GRB 990316, Radio observations
  44. GRB 990316, Optical observations
  45. GRB990316, Optical observations
  46. GRB 990316 optical observations
  47. GRB990316: simultaneous optical observation
  48. ASM/IPN error box for GRB 990308 (BATSE #7457)
  49. GRB990308 not a new SGR
  50. GRB 990308a and GRB 990308b
  51. GRB990308 (Trig. 7457), optical observations
  52. GRB981220, IPN localization
  53. GRB 981220, radio observations
  54. GRB 990123, Field Photometry
  55. GRB 990217 Optical Observations
  56. GRB 990217, radio observations
  57. Optical Observations of GRB990217
  58. GRB990123: Caltech STIS Photometry and Images
  59. GRB990123 observations
  60. GRB990123, Optical Observation
  61. GRB 990123: Discovery of the Probable Host Galaxy
  62. GRB 990123: Reduced HST Images
  63. For Immediate Posting to GCN - HST Data GRB 990123 Available
  64. GRB19990123 observations
  65. GRB 990123: BVRI standards in the field
  66. GRB 990123: Updated Keck Spectroscopy Results
  67. GRB981220, field photometry
  68. GRB 990123 NOT Spectrum Update
  69. GRB990123, Optical observation
  70. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  71. GRB 990123: Publicly available reduced HST images
  72. GRB990123, Upcoming HST Service Observations
  73. GRB 990123: New Constraints on Possible Foreground Galaxies
  74. GRB990123 Optical Observations
  75. GRB990123, Probability of gravitational lensing
  76. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  77. GRB 990123: Continued Radio Observations
  78. GRB990123, Preliminary Lens Search Results
  79. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  80. On the Lensing Interpretation of GRB 990123
  81. Search for Potential Images of GRB 990123
  82. Search for Potential Images of GRB 990123
  83. GRB990123, Optical BVRI Observations
  84. GRB 990123: near-infrared observations.
  85. GRB990123, OSSE observations
  86. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  87. "GRB 990123: New BV Observations"
  88. GRB 990123 Optical Follow-Up
  89. GRB 990123; Addendum to GCN 223
  90. GRB 990123: BATSE Observations
  91. GRB 990123 Keck Spectrum update
  92. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  93. GRB990123 Optical Observations
  94. GRB 990123 Spectroscopic Redshifts
  95. GRB 990123: New Optical Observations, Decay Measure
  96. GRB 990123 Optical Follow-Up
  97. GRB 990123: Possible Gravitationally Lensed Burst?
  98. GRB 990123 optical observations
  99. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  100. GRB 990123 radio observations

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