Skip to main content
GCN at AAS 245, Legacy Circulars Address Retirement. 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').

23953 results found.

  1. GRB 241228A: Mondy optical afterglow observations
  2. GRB 241229A: GOTO optical upper limits
  3. GRB 241228B: VLT/X-shooter redshift of z = 2.674
  4. GRB 241228A: NOT optical upper limits
  5. GRB 241228B: LCO optical observation
  6. GRB 241228A: Swift-BAT refined analysis
  7. GRB 241228B: Swift/BAT-GUANO localization skymap of a burst
  8. GRB 241228A: Fermi GBM Observation
  9. GRB241228B: GROWTH-India Telescope optical observations
  10. GRB 241228B: LCOGT photometry of the likely optical counterpart GOTO24jmz
  11. GRB 241226A: Swift/BAT-GUANO localization skymap of a burst
  12. GRB 241228A: GROWTH-India telescope optical upper limit
  13. GRB 241228B: TRT optical counterpart confirmation
  14. GRB 241228A: Swift-XRT refined Analysis
  15. GRB 241228A: Swift/UVOT Upper Limits
  16. GRB 241228A: Enhanced Swift-XRT position
  17. GRB 241228A: Swift detection of a burst
  18. IceCube-241224A: Upper limits from a search for additional neutrino events in IceCube
  19. LIGO/Virgo/KAGRA S241225c: Two counterpart neutrino candidates from IceCube neutrino searches
  20. GRB 241212A: VZLUSAT-2 detection
  21. EP241223a: Mondy AZT-33IK optical observations
  22. GRB 241029A: LCO optical observation
  23. GRB 241223A: Swift-XRT observations
  24. LIGO/Virgo/KAGRA S241225v: Identification of a GW compact binary merger candidate
  25. GRB 241029A: AbAO AS-32 optical observations
  26. GRB 241223A: Fermi GBM Detection
  27. Fermi trigger No 756678579: Global MASTER-Net observations report
  28. LIGO/Virgo/KAGRA S241225c: Identification of a GW compact binary merger candidate
  29. EP241223a
  30. EP241223a: EP-WXT detection of a fast X-ray transient
  31. EP241113a: Non-detection in Radio Follow-up Observations with eMERLIN
  32. GRB241113A: 7DT Optical upper limits
  33. GRB 241223A: GOTO optical observations summary
  34. GRB 241105A: JWST photometric observations of the host galaxy
  35. EP241217a: e-MERLIN radio observations
  36. GRB 241223A: BALROG localization (Fermi Trigger 756648531 / GRB 241223506)
  37. The EP-WXT trigger 01709129287 is likely a flaring star
  38. EP241217a: Liverpool Telescope optical upper limit
  39. EP241021a: VLA radio detection
  40. GRB 241218A: Mondy AZT-33IK optical upper limit
  41. EP241217a : Leavitt Observatory optical upper limit
  42. GRB 241217A/EP241217b: tentative VLT spectroscopic redshift z=1.879
  43. EP241217a: 1.6m Mephisto multi-band optical observations
  44. GRB 241217a/EP241217B: 1.6m Mephisto optical upper limits
  45. GRB 241218A: Swift/UVOT Upper Limits
  46. EP241217a: optical upper limit with the Liverpool Telescope
  47. GRB 241209B: EP-FXT afterglow detection
  48. GRB 241218A: NOT optical upper limits
  49. GRB 241218A: Swift-BAT refined analysis
  50. GRB 241217A / EP241217B: GRANDMA/T1MPicduMidi optical upperlimits
  51. EP 241217a: NIR detection with P200/WIRC
  52. EP 241217a: Possible J-band detection with WINTER
  53. GRB 241217A/EP241217B: Fermi-GBM Sub-Threshold Detection
  54. EP241217a: refined EP-WXT analysis and EP-FXT follow-up observations
  55. GRB 241217A / EP241217b: Nanshan/HMT optical upper limit
  56. GRB 241217A / EP241217b: NOT optical upper limits
  57. GRB 241218A: REM optical upper limit
  58. GRB 241217A/EP241217b: REM optical/NIR upper limits
  59. EP241217a: REM optical/NIR upper limits
  60. GRB 241217a: Liverpool Telescope optical follow-up
  61. EP241217a: Liverpool Telescope optical follow-up
  62. GRB 241218A: Swift-XRT refined Analysis
  63. EP241217a: NOT optical observations
  64. EP241217a: GROWTH-India Telescope optical observations
  65. GRB 241218A: NUTTelA-TAO / BSTI Optical Limits
  66. EP241119a: 7DT Optical upper limits
  67. EP241217a: Xinglong optical follow-up observations
  68. EP241217b/GRB 241217A: EP detection of the prompt X-ray emssion
  69. GRB 241218A: LCOGT Optical Upper Limit
  70. GRB 241218A: Enhanced Swift-XRT position
  71. GRB 241217A: GMG Optical Upper Limit
  72. GRB 241218A: Swift detection of a burst
  73. GRB 241217A : SVOM/VT optical afterglow detection
  74. GRB 241217A: Swift-XRT afterglow detection
  75. GRB 241217A: LCO optical upper limit
  76. GRB 241217A: GRANDMA/TAROT optical upperlimits
  77. EP241217a: Swift-XRT Detection
  78. EP241217A: Non-detection from Fermi-GBM Observations
  79. GRB 241217A : SVOM/ECLAIRs,GRM,MXT detection of a long burst with a bright X-ray afterglow candidate
  80. EP241217a: Kinder optical follow-up observations
  81. EP241217A: LCO optical observations
  82. EP241217a: Gemini-North detection of the likely optical counterpart
  83. EP241217a: EP detection of an X-ray transient
  84. EP241107a: VLA Radio Observation
  85. GRB 241213A: Swift-BAT refined analysis
  86. GRB 241214A: Swift/BAT-GUANO localization skymap of a burst
  87. GRB 241215A: Mondy AZT-33IK optical observations
  88. GRB 241212A: Swift-XRT observations
  89. GRB 241215A: Nanshan/HMT optical upper limit
  90. GRB 241215A: Montarrenti Observatory optical upper limit
  91. GRB 241215A: GROWTH-India telescope optical upper limit
  92. GRB 241215A: A long GRB detected by INTEGRAL
  93. Integral GRB241215.58: Global MASTER-Net observations report
  94. GRB 241213B: Swift-XRT observations
  95. GRB 241213A: Swift/UVOT Upper Limits
  96. GRB 241213A: Swift-XRT refined Analysis
  97. GRB 241212A: Fermi GBM detection
  98. EP241208a: NOT optical upper limits
  99. GRB 241213A: LCOGT Optical Upper Limits
  100. GRB 241213B: MAXI/GSC detection

Advanced

Download all Circulars as a .tar.gz archive:
Looking for U.S. government information and services? Visit USA.gov