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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

32532 results found.

  1. LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
  2. LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
  3. Konus-Wind detection of GRB 241115D / EP 241115a
  4. LIGO/Virgo/KAGRA S241125n: HCT upper limit
  5. LIGO/Virgo/KAGRA S241125n: Upper limits from Konus-Wind observations
  6. GRB 241026A: radio detection with the VLA
  7. EP241125a: Optical upper limit with Kinder observations
  8. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on a Optical Counterpart at the BAT Position
  9. LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
  10. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  11. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  12. LIGO/Virgo/KAGRA S241125n: Updated Sky localization
  13. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  14. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  15. LIGO/Virgo/KAGRA S241125n: Updated Sky localization and Coincidence with External Event
  16. LIGO/Virgo/KAGRA S241125n: Swift/BAT-GUANO candidate counterpart
  17. GRB 241120A: GRBAlpha detection
  18. GRB 241113B: SVOM/VT optical afterglow observations
  19. LIGO/Virgo/KAGRA S241125n: Identification of a GW compact binary merger candidate
  20. Konus-Wind detection of GRB 241117A
  21. LIGO/Virgo/KAGRA S241122a: Updated Sky localization and Source Classification
  22. GRB 241105A: ATCA radio detection
  23. LIGO/Virgo/KAGRA S241122a: Identification of a GW compact binary merger candidate
  24. IPN triangulation of GRB 241117A
  25. GRB 241026A: VIRT Optical Upper Limit
  26. GRB 241025A: VIRT Optical Upper Limit
  27. Konus-Wind detection of GRB 241120A
  28. GRB241120A: OHP/T193 optical observations
  29. GRB 241120A: CALET Gamma-Ray Burst Monitor detection
  30. EP241021a and EP241026b: Keck/LRIS spectroscopic observations
  31. EP trigger ID 01709065118: Keck/LRIS spectroscopic observations
  32. EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope
  33. GRB 241120A: Mondy and AbAO optical observations
  34. EP241119a: Optical upper limits with Kinder observations
  35. EP241119a: GIT optical upper limits
  36. GRB 241113A: Possible ATCA Radio detection
  37. EP241119a : J-band observations with WINTER
  38. GRB 241120A: Fermi GBM Observation
  39. EP241119a: Global MASTER-Net observations report
  40. GRB241120A: a long GRB detected by INTEGRAL
  41. GRB 241115A: CALET Gamma-Ray Burst Monitor detection
  42. GRB 241112B: Mephisto further optical observations
  43. GRB 241030A: J-band observations
  44. GRB 241115a: PRIME near-infrared upper limits
  45. GRB 241117A: Swift/BAT-GUANO localization skymap of a burst
  46. GRB 241115B: Fermi GBM Observation
  47. LIGO/Virgo/KAGRA S241114y: Updated Sky localization
  48. Fermi GRB 241118A: Global MASTER-Net observations report
  49. Updates to IceCube realtime alert system for muon tracks
  50. GRB 241117A: SVOM/GRM observation of a short burst with extended emission
  51. Fermi GRB 241117B: Global MASTER-Net observations report
  52. LIGO/Virgo/KAGRA S241116cq: Updated Sky localization
  53. GRB 241115B: Swift/BAT-GUANO localization skymap of a long burst
  54. Fermi GRB 241117A: Global MASTER-Net observations report
  55. GRB 241115C: Fermi GBM Observation
  56. LIGO/Virgo/KAGRA S241116cq: Identification of a GW compact binary merger candidate
  57. EP241115a/GRB 241115D: Optical upper limits with Kinder observations
  58. GRB 241115A: Mephisto upper limits
  59. GRB 241113B: Mephisto upper limits
  60. EP241115a/GRB 241115D: Swift/XRT follow-up observation
  61. GRB 241115D / EP 241115a: SVOM/GRM observation
  62. The EP-WXT trigger 01709120856 is likely a flaring star
  63. EP241113a: Swift XRT weak detection
  64. GRB 241115A: Fermi GBM Observation
  65. GRB 241115A: LCOGT Optical Upper Limits
  66. Fermi GRB 241115B: Global MASTER-Net observations report
  67. LIGO/Virgo/KAGRA S241114bi: Updated Sky localization and EM Bright Classification
  68. EP241115a: Global MASTER-Net observations report
  69. LIGO/Virgo/KAGRA S241113p: Updated Sky localization
  70. EP241113a: No Detection in Fermi-GBM Observations
  71. Swift GRB 241115A: Global MASTER-Net observations report
  72. Fermi GRB 241115A: Global MASTER-Net observations report
  73. EP 241113a: LBT possible optical counterpart
  74. GRB 241113B: KAIT Optical Afterglow Candidate
  75. LIGO/Virgo/KAGRA S241114bi: Upper limits from Fermi-GBM Observations
  76. GRB 241113A: Swift-BAT refined analysis
  77. LIGO/Virgo/KAGRA S241114bi: Identification of a GW compact binary merger candidate
  78. GRB 241113A: PRIME near-infrared upper limits
  79. Fermi GRB 241114A: Global MASTER-Net observations report
  80. EP241113a: Global MASTER-Net observations report
  81. GRB 241113B: J-band upper limit from WINTER
  82. GRB 241113A: J-band observations with WINTER
  83. EP241113a : J-band observations with WINTER
  84. GRB 241030A: LCO optical observation
  85. IceCube-241113A: Upper limits from a search for additional neutrino events in IceCube
  86. GRB 241113A: 1.6m Mephisto and 50cm array optical upper limits
  87. GRB 241113A: KAIT optical observations
  88. EP241113b: Global MASTER-Net observations report
  89. EP241113b/GRB 241113B: EP detection of GRB 241113B
  90. Fermi-LAT gamma-ray observations of IceCube-241113A
  91. GRB 241113B: SVOM/GRM observation
  92. LIGO/Virgo/KAGRA S241114y: Identification of a GW compact binary merger candidate
  93. EP241107a: SOAR upper limits
  94. GRB 241113A: Swift/UVOT Detection
  95. GRB 241113A: REM detection of the optical/NIR afterglow
  96. Konus-Wind detection of GRB 241107A (short/hard)
  97. LIGO/Virgo/KAGRA S241113p: Identification of a GW compact binary merger candidate
  98. GRB 241113B: Swift ToO observations
  99. GRB 241113A: LCO optical observations
  100. GRB 241112B: GMG Optical Upper Limit

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