Skip to main content
Circulars over Kafka event name backfill. 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').

19109 results found.

  1. GRB990123, Preliminary Lens Search Results
  2. GRB990123, Optical BVRI Observations
  3. GRB 990123: near-infrared observations.
  4. GRB990123, OSSE observations
  5. GRB990123: NIR Observation
  6. "GRB 990123: New BV Observations"
  7. GRB 990123: New Optical Observations, Decay Measure
  8. GRB 990123 Optical Follow-Up
  9. GRB 990123: Possible Gravitationally Lensed Burst?
  10. GRB990123, optical observation
  11. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  12. GRB 990123 r-band photometry
  13. GRB 990123 Optical Follow-up
  14. GRB990123, early optical counterpart detection
  15. GRB 990123, Radio observations
  16. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  17. Possible identification of SN1999E with GRB980910
  18. Optical Observations of GRB 981220
  19. GRB 981226: radio variable
  20. GRB 981226 Optical Observations
  21. GRB981226 BeppoSAX follow up
  22. GRB 981226
  23. GRB 981226 optical observations
  24. GRB981220 B, R and I band observations
  25. GRB 981220:Optical Observations
  26. GRB 981226 optical observations
  27. GRB 981220, radio observations
  28. GRB 981220: BeppoSAX/GRBM results
  29. GRB981220 Optical Observations
  30. GRB 981220
  31. GRB 980326/Host Galaxy
  32. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  33. BeppoSAX NFI Observation of GRB980425
  34. GRB980329 R,I flux calibration and R,I,K upper limits
  35. GRB980425 Optical Follow-up
  36. GRB980425: X-ray revised positions
  37. GRB980703 Very Long Baseline Interferometry
  38. GRB970508 optical observations
  39. GRB980519, Optical Observations
  40. GRB980703 - BeppoSAX/GRBM detection
  41. GRB980703 optical photometry
  42. GRB 980703: BATSE Observations
  43. GRB980703 optical observations
  44. GRB980703: Radio transient
  45. GRB980703 Transient Optical Follow-Up
  46. GRB980703: LOTIS observation at early times
  47. GRB980613 Optical Observations
  48. GRB 980703
  49. BeppoSAX NFI observations of GRB 980703
  50. GRB980703 optical followup
  51. Radio observations of SGRs
  52. SGR1900+14 field optical observations
  53. GRB 980613: Optical transient and its host galaxy
  54. SGR1627-41, RXTE/ASM observations
  55. GRB 980613: Detection of the probable host galaxy
  56. GRB 980613 Optical Observations
  57. GRB 980613 optical observations
  58. Discovery of a new SGR source, SGR1627-41
  59. GRB980613 Optical Observations
  60. GRB980613 observations from Palomar
  61. GRB980613 Near Infra-Red Observations
  62. GRB980613, BeppoSAX WFC positions
  63. GRB971214 Secondary Standards
  64. GRB980519 Secondary Standards
  65. GRB 980519 Optical Observations
  66. GRB 980519
  67. GRB980519 optical observations
  68. GRB 980519 Optical Observations
  69. GRB980519 BATSE Observations
  70. GRB970519, optical follow-up at Schmidt Calern
  71. GRB980519 Optical Observations
  72. GRB 980519 Optical Observations
  73. GRB980515, BeppoSAX IAUC to be submitted
  74. GRB980519, BeppoSAX-WFC position
  75. BeppoSAX GRB ALERT: updated position of grb980515
  76. GRB 980425 Brightness Temperature
  77. BSAX Observations of GRB980425 field
  78. SAX J0840.7+2248 Optical Observations
  79. GRB980425: optical obs.
  80. GRB980425: Radio Observations
  81. report on BSAX observations of GRB980425
  82. GRB980326 X-ray Observations
  83. GRB980326, optical observations
  84. GRB980326, optical observations
  85. GRB980329 Keck K-band observations
  86. GRB980329 sub-millimeter observations
  87. GRB980326 optical observations
  88. GRB980329 optical observations
  89. GRB980329 VLA observations
  90. GRB980329 optical observations
  91. GRB980326 optical observations
  92. Optical Observations of GRB 970508
  93. GRB 971214: Redshift from Keck Observations
  94. Near-IR follow-up on GRB 971227
  95. Optical Observations of the GRB 971227 field
  96. Optical Observations on GRB 971227
  97. GRB971227: Plaskett R-band observations
  98. GRB 971227: Optical clarifications
  99. GRB971227: Further CAHA R-band images
  100. GRB971227: LOTIS observations

Advanced

Download all Circulars as a .tar.gz archive:
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