Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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"

23578 results found.

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

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov